Update README supported and unsupported Features section

[robwalch]

This PR will...

Update README supported and unsupported Features section:

• Moved or added notes for tags that we parse and list under Supported, but do not support functionally. For Example:

The following tags are added to their respective fragment's attribute list but are not
implemented in streaming and playback
  - #EXT-X-GAP (Not implemented. See #2940)

• Moved Not Supported (Yet) to Not Supported under Features
• Moved Server-side-rendering (SSR)... to follow Not Supported and updated the description to explicitly state that only a dummy object is exported in node.js and that hls.js is not instantiable in that runtime.
• Updated the hls.js spec link to draft-pantos-hls-rfc8216bis-08
• Added JW Player to Player Integration
• Moved They use hls.js in production! under Player Integration

Clean up prettier ignore and remove bower config.

Why is this Pull Request needed?

The Features section is an important resource for understanding what hls.js does and does not support.

Prettier should not clean up files generated in the /lib directory.

We no longer publish to bower.

Are there any points in the code the reviewer needs to double check?

• Are there any other HLS tags or sections of the spec not covered in the Not Supported section?
• Are there any other open issues or pull-requests worth covering in the Not Supported section?

I'll take suggestions for enhancing the supported features section, but adding features or additional writing beyond any missing tags or attributes is outside the scope of this PR.

Checklist

• changes have been done against master branch, and PR does not conflict
• new unit / functional tests have been added (whenever applicable)
• API or design changes are documented in API.md

[tjenkinson]

LGTM!

Are there any other HLS tags or sections of the spec not covered in the Not Supported section?

Are there any other open issues or pull-requests worth covering in the Not Supported section?

I haven't checked these though