Rename Padding -> Margin.

[colinrtwhite]

Also renames start/end -> left/right. Left/right fits better with the flexbox spec and we don't support right-to-left layouts.

Follow up from the conversation here: #855

[veyndan]

Also renames start/end -> left/right. Left/right fits better with the flexbox spec and we don't support right-to-left layouts.

Have you got a link to the spec? I'm kinda surprised because CSS logical properties are promoted pretty heavily (e.g., flex-start).

[colinrtwhite]

@veyndan Margin isn't really part of the flexbox spec so it uses the default CSS left/right names for margin: https://www.w3schools.com/css/css_margin.asp

[veyndan]

True, flex-start was a bad/wrong example. Margin's logical property counterparts to margin-left/margin-right are margin-inline-start/margin-inline-end. I'm just a bit concerned going with left/right as it's exclusionary of RTL (and vertical) writing modes.

[JakeWharton]

It does seem very weird to not use start/end in anything newly built.

[colinrtwhite]

@veyndan That's a good point. I figured that using left/right was more in-line with web, but that seems incorrect. I'll revert back to start/end.