Compile inclusive feature design documentation for community sharing

[brettfiedler]

@terracoda and I met to locate all the relevant documentation so that we can at least point to it for now and have a better sense of where it should go.

• https://github.com/phetsims/sun/tree/main/doc (Component-level design documentation)

• https://github.com/phetsims/phet-info/tree/main/doc (Dev-centric quick start implementations, with some design info implicitly included alongside)

• https://github.com/phetsims/tambo/tree/main/doc

• https://github.com/phetsims/scenery-phet/tree/aeda20765bba628de8e1d0c8c213d9f3de257b9b/js/accessibility

• https://github.com/phetsims/joist/blob/9facb5cc9689f92fc9ca764eb40660c44d46e175/doc/PhetMenu.md?plain=1#L15

• Description Course Resources

  • And in particular: Description Framework in Brief
  • Worth including updated image somewhere:
    • 

• DRAFT PhET Voicing and Description Tips

• Tier 1 Description Design and Tips

• Sound Design Guidelines

• Sound and Sonification Course and materials

• Haptics Playground

Old, unmaintained and possibly redundant

• Alternative Input Design Template
• Keyboard Navigation
• Complex Controls and Interaction
• Inclusive Design Coursera Course