Reorganise some docs, remove repeated content

Author: penelopeysm

_quarto.yml

@@ -50,15 +50,14 @@ website:
     - text: documentation
       collapse-level: 1
       contents: 
-        - section: "Documentation"
+        - section: "For Users"
           # href: tutorials/index.qmd, This page will be added later so keep this line commented
           contents:
-          - section: "Using Turing - Modelling Syntax and Interface"
+          - section: "Using the Turing library"
             collapse-level: 1
             contents: 
               - tutorials/docs-00-getting-started/index.qmd
-              - text: "Quick Start"
-                href: tutorials/docs-14-using-turing-quick-start/index.qmd
+              - tutorials/00-introduction/index.qmd
               - tutorials/docs-12-using-turing-guide/index.qmd
               - text: "Mode Estimation"
                 href: tutorials/docs-17-mode-estimation/index.qmd
@@ -70,9 +69,8 @@ website:
               - text: "External Samplers"
                 href: tutorials/docs-16-using-turing-external-samplers/index.qmd
 
-          - section: "Using Turing - Tutorials"
+          - section: "Examples of Turing Models"
             contents: 
-              - tutorials/00-introduction/index.qmd
               - text: Gaussian Mixture Models
                 href: tutorials/01-gaussian-mixture-model/index.qmd
               - tutorials/02-logistic-regression/index.qmd
@@ -97,13 +95,15 @@ website:
               - text: "Gaussian Process Latent Variable Models"
                 href: tutorials/12-gplvm/index.qmd
 
-          - section: "Developers: Contributing"
+        - section: "For Developers"
+          contents:
+          - section: "Contributing"
             collapse-level: 1
             contents:
               - text: "How to Contribute"
                 href: tutorials/docs-01-contributing-guide/index.qmd
 
-          - section: "Developers: PPL"
+          - section: "How Turing Works"
             collapse-level: 1
             contents:
               - tutorials/docs-05-for-developers-compiler/index.qmd

tutorials/docs-12-using-turing-guide/index.qmd

@@ -1,5 +1,5 @@
 ---
-title: Guide
+title: "Turing's Core Functionality"
 engine: julia
 ---
 
@@ -10,6 +10,8 @@ using Pkg;
 Pkg.instantiate();
 ```
 
+This article provides an overview of the core functionality in Turing.jl, which are likely to be used across a wide range of models.
+
 ## Basics
 
 ### Introduction