Update: add mapping tables for customizable select

[scottaohara]

Initial draft of select / button as child of a select mappings.

Test, Documentation and Implementation tracking

Once this PR has been reviewed and has consensus from the working group, tests should be written and issues should be opened on browsers. Add N/A and check when not applicable.

• [ ] "author MUST" tests:
• [ ] "user agent MUST" tests:
• [ ] Browser implementations (link to issue or commit):
  • WebKit:
  • Gecko:
  • Blink:
• [ ] Does this need AT implementations?
• [ ] Related APG Issue/PR:
• [ ] MDN Issue/PR:

[netlify[bot]]

✅ Deploy Preview for wai-aria ready!

Name	Link
🔨 Latest commit	df2b946531040b893a26e77e492f2670af93570e
🔍 Latest deploy log	https://app.netlify.com/projects/wai-aria/deploys/68c044808815d30008ad69eb
😎 Deploy Preview	https://deploy-preview-2369--wai-aria.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.