Make doc structure consistent and up-to-date

This is part of an effort to make the Kivy sibling projects' documentation
structure consistent and up-to-date.

Unrelated fixes:
* Documentation version number now fetched from `buildozer/__init__.py`. Addresses kivy#1738
* Implemented many/all of the formatting changes from kivy#1708.
* Copy-edit of documents.
   * Contents of Contributing.rst moved to CONTRIBUTING.md
   * Removed installation intructions from README.md, so there is only one
     version.
   * Added Recipes description to RST documentation
   * Removed broken index page

CHECKLIST

* CONTRIBUTING.md
   [x] If repo takes user contributions, is present
   [x] In root dir (not .github dir)
   [x] Explains relationship to Kivy, if unclear.
   [x] Refers to kivy/kivy Contribution Guidelines.

* LICENSE
   [X] If repo takes user contributions, is present.
   [X] Acknowledges the range of years to 2023.
   [X] Acknowledges Kivy Team and other contributors
   [X] Mentions it is an MIT License.

* CODE_OF_CONDUCT.md
   [X] If repo takes user contributions or hosts discussions, is present.
   [X] Refers to kivy/kivy CODE_OF_CONDUCT.md

* CONTACT.md
   [X] Refers to kivy/kivy CONTACT.md

* FAQ.md
   [x] If repo is big enough for RST documentation, is present.

* README:
   [x] Is a Markdown file.
   [x Describes the project.
   [x] Describes its place in the Kivy sibling projects.
   [x] If Documentation exists, mention it.
   [x] If CONTRIBUTING exists, mentions it.
   [x] If LICENSE exists, mentions it.
   [x] If CODE_OF_CONDUCT exists, mentions it.
   [x] Mentions kivy/kivy CONTACT.md
   [NA] Uses Python syntax colouring for embedded Python code.
   [x] Uses badges to display current status, including:
        [x] Backers
		[x] Sponsors
		[x] GitHub contributors
		[x] Contributor Covenant
		[x] PyPI Version
		[x] PyPI Python Version
		[x] Build/Test status

   [x] Displays all contributors to the repo.
   [x] Displays backers
   [x] Displays top sponsors.

* RST documentation, if present
   [x] Describes the project.
   [x] Describes its place in the Kivy sibling projects.
   [x] Mentions (Kivy/Kivy) Contact Us link.
   [x] Mentions LICENSE.
   [x] Mentions CONTRIBUTING
   [x] Mentions FAQ
   [x] conf.py mentioned Kivy Team and other contributors
		- copyright, latex_documents, man_pages, texinfo documents

* WORKFLOWS
   [x] NO_RESPONSE.yml is present if the repo has awaiting_reply tag.
   [x] NO_RESPONSE uses latest script versions.
   [x] SUPPORT.yml is present if the repo has a `support` tag.
   [x] SUPPORT.yml refers to repo's CONTACT.md

* setup.py/cfg, if present and on PyPI
   [x] Supplies description to PyPI
   [x] Supplies Python versions to PyPI
   [x] Supplies Documentation, if any, to PyPI

.github/workflows/support.yml

@@ -16,7 +16,7 @@ jobs:
   action:
     runs-on: ubuntu-latest
     steps:
-      - uses: dessant/support-requests@v3
+      - uses: dessant/support-requests@v4
         with:
           github-token: ${{ github.token }}
           support-label: 'support'

CODE_OF_CONDUCT.md

@@ -0,0 +1,8 @@
+In the interest of fostering an open and welcoming community, we as 
+contributors and maintainers need to ensure participation in our project and 
+our sister projects is a harassment-free and positive experience for everyone. 
+It is vital that all interaction is conducted in a manner conveying respect, 
+open-mindedness and gratitude.
+
+Please consult the [latest Kivy Code of Conduct](https://github.com/kivy/kivy/blob/master/CODE_OF_CONDUCT.md).
+

CONTACT.md

@@ -0,0 +1,6 @@
+# Contacting the Kivy Team
+
+If you are looking to contact the Kivy Team (who are responsible for managing
+the Buildozer project), including looking for support, please see our
+latest [Contact Us](https://github.com/kivy/kivy/blob/master/CONTACT.md) 
+document.

CONTRIBUTING.md

@@ -0,0 +1,67 @@
+# Contribution Guidelines
+
+Buildozer is part of the [Kivy](https://kivy.org) ecosystem - a large group of
+products used by many thousands of developers for free, but it
+is built entirely by the contributions of volunteers. We welcome (and rely on) 
+users who want to give back to the community by contributing to the project.
+
+Contributions can come in many forms. See the latest 
+[Contribution Guidelines](https://github.com/kivy/kivy/blob/master/CONTRIBUTING.md)
+for general guidelines of how you can help us.
+
+---
+
+If you would like to work on Buildozer, you can set up a development build:
+```bash
+git clone https://github.com/kivy/buildozer
+cd buildozer
+python setup.py build
+pip install -e .
+```
+---
+
+Buildozer uses python-for-android, that is architected to be extensible with 
+new recipes and new bootstraps.
+
+If you do develop a new recipe on python-for-android, here is how to test it:
+
+#. Fork `Python for Android <https://github.com/kivy/python-for-android>`_, and
+   clone your own version (this will allow easy contribution later)::
+
+```bash
+git clone https://github.com/YOURNAME/python-for-android
+```
+
+#. Change your `buildozer.spec` to reference your version::
+
+     p4a.source_dir = /path/to/your/python-for-android
+
+#. Copy your recipe into `python-for-android/recipes/YOURLIB/recipe.sh`
+
+#. Rebuild.
+
+When your recipe works, you can ask us to
+include it in the python-for-android project, by issuing a Pull Request:
+
+#. Create a branch::
+
+```bash
+git checkout --track -b recipe-YOURLIB origin/master
+```
+
+#. Add and commit::
+
+```bash
+git add python-for-android/recipes/YOURLIB/*
+git commit -am 'Add support for YOURLIB`
+```  
+
+#. Push to GitHub
+
+```bash
+git push origin master
+```
+
+#. Go to `https://github.com/YOURNAME/python-for-android`, and you should see
+   your new branch and a button "Pull Request" on it. Use it, write a
+   description about what you did, and Send!

FAQ.md

@@ -0,0 +1,31 @@
+# FAQ for Buildozer
+
+## Introduction
+
+Buildozer is a development tool for turning  [Python](https://www.python.org/)
+applications into binary packages ready for installation on any of a number of
+platforms, including mobile devices.
+
+The app developer provides a single "buildozer.spec" file, which describes the
+application's requirements and settings, such as title and icons. Buildozer can
+then create installable packages for Android, iOS, Windows, macOS and/or Linux.
+
+Buildozer is managed by the [Kivy Team](https://kivy.org/about.html). It relies
+on its sibling projects: 
+[python-for-android](https://github.com/kivy/python-for-android/) and 
+[Kivy for iOS](https://github.com/kivy/kivy-ios/). It has features to make
+building apps using the [Kivy framework](https://github.com/kivy/kivy) easier,
+but it can be used independently - even with other GUI frameworks.
+
+## How do I write my own recipes?
+
+Instructions on how to write your own recipes is available in the
+[Kivy for iOS](https://github.com/kivy/kivy-ios/) and
+[python-for-android documentation](https://python-for-android.readthedocs.io/en/latest/recipes/).
+
+Instructions on how to test your own recipes from Buildozer is available in the
+[Buildozer Contribution Guidelines](CONTRIBUTING.md).
+
+> [!NOTE]
+> This document is very short at the moment. Please contribute some FAQ
+> questions and answers.