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

Unrelated fixes:
* Mild copy-edit of README
* Mention it only works on macOS

CHECKLIST

* CONTRIBUTING.md
   [x] If repo takes user contributions, is present
   [x] In root dir (not .github dir)
   [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
   [NA] If repo is big enough for RST documentation, is present.
   ** Added anyway because it was bloating the README **

* README:
   [x] Is a Markdown file.
   [x] Describes the project.
   [x] Describes its place in the Kivy sibling projects.
   [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.

* RST documentation, if present
   [NA] Describes the project.
   [NA] Describes its place in the Kivy sibling projects.
   [NA] Mentions LICENSE.
   [NA] Mentions CONTRIBUTING
   [NA] Mentions CODE_OF_CONDUCT
   [NA] Mentions FAQ

* 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 kivy/kivy CONTACT.md

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

Co-authored-by: Mirko Galimberti <me@mirkogalimberti.com>