documentation enhancements (#1603)

- Add documentation for the Hugging Face concepts library and TI embedding.

- Fixup index.md to point to each of the feature documentation files,
  including ones that are pending.

Author: lstein

docs/assets/concepts/image1.png

@@ -269,6 +269,12 @@ value, we are insisting on a more stringent classification.
 invoke> a piece of cake -I /path/to/breakfast.png -tm bagel 0.6
 ```
 
+### Custom Styles and Subjects
+
+You can load and use hundreds of community-contributed Textual
+Inversion models just by typing the appropriate trigger phrase. Please
+see [Concepts Library](CONCEPTS.md) for more details.
+
 # Other Commands
 
 The CLI offers a number of commands that begin with "!".

docs/assets/concepts/image2.png

@@ -0,0 +1,132 @@
+---
+title: The Hugging Face Concepts Library and Importing Textual Inversion files
+---
+
+# :material-file-document: Concepts Library
+
+## Using Textual Inversion Files
+
+Textual inversion (TI) files are small models that customize the output of
+Stable Diffusion image generation. They can augment SD with
+specialized subjects and artistic styles. They are also known as
+"embeds" in the machine learning world.
+
+Each TI file introduces one or more vocabulary terms to the SD
+model. These are known in InvokeAI as "triggers." Triggers are often,
+but not always, denoted using angle brackets as in
+"<trigger-phrase>". The two most common type of TI files that you'll
+encounter are `.pt` and `.bin` files, which are produced by different
+TI training packages. InvokeAI supports both formats, but its [built-in
+TI training system](TEXTUAL_INVERSION.md) produces `.pt`.
+
+The [Hugging Face company](https://huggingface.co/sd-concepts-library)
+has amassed a large ligrary of >800 community-contributed TI files
+covering a broad range of subjects and styles. InvokeAI has built-in
+support for this library which downloads and merges TI files
+automatically upon request. You can also install your own or others'
+TI files by placing them in a designated directory.
+
+### An Example
+
+Here are a few examples to illustrate how it works. All these images
+were generated using the command-line client and the Stable Diffusion
+1.5 model:
+
+Japanese gardener
+<br>
+<img src="../assets/concepts/image1.png">
+
+Japanese gardener &lt;ghibli-face&gt;
+<br>
+<img src="../assets/concepts/image2.png">
+
+Japanese gardener &lt;hoi4-leaders&gt;
+<br>
+<img src="../assets/concepts/image3.png">
+
+Japanese gardener &lt;cartoona-animals&gt;
+<br>
+<img src="../assets/concepts/image4.png">
+
+You can also combine styles and concepts:
+
+A portrait of &lt;alf&gt; in &lt;cartoona-animal&gt; style
+<br>
+<img src="../assets/concepts/image5.png">
+
+## Using a Hugging Face Concept
+
+Hugging Face TI concepts are downloaded and installed automatically as
+you require them. This requires your machine to be connected to the
+Internet. To find out what each concept is for, you can browse the
+[Hugging Face concepts
+library](https://huggingface.co/sd-concepts-library) and look at
+examples of what each concept produces.
+
+When you have an idea of a concept you wish to try, go to the
+command-line client (CLI) and type a "&lt;" character and the beginning
+of the Hugging Face concept name you wish to load.  Press the Tab key,
+and the CLI will show you all matching concepts. You can also type "&lt;"
+and Tab to get a listing of all ~800 concepts, but be prepared to
+scroll up to see them all! If there is more than one match you can
+continue to type and Tab until the concept is completed.
+
+For example if you type "&lt;x" and Tab, you'll be prompted with the completions:
+
+```
+<xatu2>        <xatu>         <xbh>          <xi>           <xidiversity>  <xioboma>      <xuna>         <xyz>          
+```
+
+Now type "id" and press Tab. It will be autocompleted to
+"&lt;xidiversity&gt;" because this is a unique match.
+
+Finish your prompt and generate as usual. You may include multiple
+concept terms in the prompt.
+
+If you have never used this concept before, you will see a message
+that the TI model is being downloaded and installed. After this, the
+concept will be saved locally (in the `models/sd-concepts-library`
+directory) for future use.
+
+Several steps happen during downloading and
+installation, including a scan of the file for malicious code. Should
+any errors occur, you will be warned and the concept will fail to
+load. Generation will then continue treating the trigger term as a
+normal string of characters (e.g. as literal "&lt;ghibli-face&gt;").
+
+Currently auto-installation of concepts is a feature only available on
+the command-line client. Support for the WebUI is a work in progress.
+
+## Installing your Own TI Files
+
+You may install any number of `.pt` and `.bin` files simply by copying
+them into the `embeddings` directory of the InvokeAI runtime directory
+(usually `invokeai` in your home directory). You may create
+subdirectories in order to organize the files in any way you wish. Be
+careful not to overwrite one file with another. For example, TI files
+generated by the Hugging Face toolkit share the named
+`learned_embedding.bin`. You can use subdirectories to keep them
+distinct.
+
+At startup time, InvokeAI will scan the `embeddings` directory and
+load any TI files it finds there. At startup you will see a message
+similar to this one:
+
+```
+>> Current embedding manager terms: *, <HOI4-Leader>, <princess-knight>
+```
+
+Note the "*" trigger term. This is a placeholder term that many early
+TI tutorials taught people to use rather than a more descriptive
+term. Unfortunately, if you have multiple TI files that all use this
+term, only the first one loaded will be triggered by use of the term.
+
+To avoid this problem, you can use the `merge_embeddings.py` script to
+merge two or more TI files together. If it encounters a collision of
+terms, the script will prompt you to select new terms that do not
+collide. See [Textual Inversion](TEXTUAL_INVERSION.md) for details.
+
+## Further Reading
+
+Please see [the repository](https://github.com/rinongal/textual_inversion) and
+associated paper for details and limitations.

docs/assets/concepts/image3.png

@@ -133,29 +133,6 @@ outputs = g.txt2img("a unicorn in manhattan")
 
 Outputs is a list of lists in the format [filename1,seed1],[filename2,seed2]...].
 
-Please see ldm/generate.py for more information. A set of example scripts is coming RSN.
+Please see the documentation in ldm/generate.py for more information.
 
 ---
-
-## **Preload Models**
-
-In situations where you have limited internet connectivity or are blocked behind a firewall, you can
-use the preload script to preload the required files for Stable Diffusion to run.
-
-The preload script `scripts/preload_models.py` needs to be run once at least while connected to the
-internet. In the following runs, it will load up the cached versions of the required files from the
-`.cache` directory of the system.
-
-```bash
-(invokeai) ~/stable-diffusion$ python3 ./scripts/preload_models.py
-preloading bert tokenizer...
-Downloading: 100%|██████████████████████████████████| 28.0/28.0 [00:00<00:00, 49.3kB/s]
-Downloading: 100%|██████████████████████████████████| 226k/226k [00:00<00:00, 2.79MB/s]
-Downloading: 100%|██████████████████████████████████| 455k/455k [00:00<00:00, 4.36MB/s]
-Downloading: 100%|██████████████████████████████████| 570/570 [00:00<00:00, 477kB/s]
-...success
-preloading kornia requirements...
-Downloading: "https://github.com/DagnyT/hardnet/raw/master/pretrained/train_liberty_with_aug/checkpoint_liberty_with_aug.pth" to /u/lstein/.cache/torch/hub/checkpoints/checkpoint_liberty_with_aug.pth
-100%|███████████████████████████████████████████████| 5.10M/5.10M [00:00<00:00, 101MB/s]
-...success
-```

docs/assets/concepts/image4.png

@@ -119,6 +119,26 @@ You wil need one of the following:
     ```bash
     (invokeai) ~/InvokeAI$ python scripts/invoke.py --full_precision
     ```
+## :octicons-gift-24: InvokeAI Features
+
+- [The InvokeAI Web Interface](features/WEB.md)
+  - [WebGUI hotkey reference guide](features/WEBUIHOTKEYS.md)
+  - [WebGUI Unified Canvas for Img2Img, inpainting and outpainting](features/UNIFIED_CANVAS.md)
+
+- [The Command Line Interace](features/CLI.md)
+  - [Image2Image](features/IMG2IMG.md)
+  - [Inpainting][(features/INPAINTING.md)
+  - [Outpainting](features/OUTPAINTING.md)
+  - [Adding custom styles and subjects](features/CONCEPTS.md)
+  - [Upscaling and Face Reconstruction](features/POSTPROCESS.md)
+
+- [Generating Variations](features/VARIATIONS.md)
+
+- [Prompt Engineering](features/PROMPTS.md)
+
+- Miscellaneous
+  - [Embiggen upscaling](features/EMBIGGEN.md)
+  - [Other](features/OTHER.md)
 
 ## :octicons-log-16: Latest Changes