Add list of css features in markdown by category and propose RFC

[una]

A few suggestions for this list as per discussion:

1. Put a clear headline that this is a draft list and not final
2. Add the MDN links (as linked through in the doc we all worked on) on the feature name
3. Add some indicator (like an emoji) for features we already flagged for discussion
4. Reduce subheadings, i.e. "flex properties" should go under "flexbox", "math functions" combined with "trigonometric functions", etc.
5. Remove "properies", "modern", and "CSS" from titles

[brechtDR]

A few suggestions for this list as per discussion:

1. Put a clear headline that this is a draft list and not final

Done

2. Add the MDN links (as linked through in the doc we all worked on) on the feature name

Ongoing (done for CSS4)

3. Add some indicator (like an emoji) for features we already flagged for discussion

TBD in a meeting? "Which emoji, which items". We might have changed opinions a bit. Might be good to go over them next meeting.

4. Reduce subheadings, i.e. "flex properties" should go under "flexbox", "math functions" combined with "trigonometric functions", etc.

Done

5. Remove "properies", "modern", and "CSS" from titles

Done

[brechtDR]

Added all the links I could find, some were missing. Few noteworthy things

• Animating on a path is CSS4, but we have a bunch of animation offsets in CSS5, might've been an oversight?
• View transitions in general was part of CSS5 while the rest was in future, so moved those together.
• There were indeed a few missing, I added a to-sort under CSS4, maybe something we can pick up in next meeting

There were a few that didn't have a link, we might want to check those out in detail. they could be wrong of location as well

[Que-tin]

https://github.com/CSS-Next/css-next/issues/89