Document the developement process for Formatter

Author: Pierre-Sassoulas

README.md

@@ -24,7 +24,7 @@ options:
   -v, --version  Show version number and exit
 ```
 
-### Confiuguration
+### Configuration
 
 Pydocstringformatter will also read any configuration added to the `[tool.pydocstringformatter]` section of a `pyproject.toml` file.
 
@@ -86,8 +86,17 @@ multi-line docstring
 
 ## Development
 
+### Linting
+
 Use `pre-commit install` to install the pre-commit hook for the repository.
 
+### Creating a new formatter
+
+- Implement a Formatter by inheriting from ``pydocstringformatter.formatting.Formatter``
+- Add your new formatter to ``pydocstringformatter.formatting.FORMATTERS``
+- Create a clear docstring because this will be user-facing: it's what will be seen in the help.
+- Choose a proper name because this will be user-facing: the name will be used for option of the CLI.
+
 ### Testing
 
 To run all the tests:

pydocstringformatter/formatting/__init__.py

@@ -1,4 +1,4 @@
-__all__ = ["FORMATTERS"]
+__all__ = ["FORMATTERS", "Formatter"]
 
 from typing import List
 

pydocstringformatter/formatting/base.py

@@ -6,7 +6,15 @@ class Formatter:
     """Base class for docstring formatter"""
 
     optional = False
-    name: str
+
+    @property
+    @abc.abstractmethod
+    def name(self) -> str:
+        """Name of the Formatter, chose wisely, this is an API.
+
+        This will be used to create argparse options when added to
+        'pydocstringformatter.formatting.FORMATTERS'.
+        """
 
     @abc.abstractmethod
     def treat_token(self, tokeninfo: tokenize.TokenInfo) -> tokenize.TokenInfo: