[css-sizing-3] Rename spec to CSS Box Sizing

[fantasai]

Current title of the css-sizing-3 is "CSS Intrinsic and Extrinsic Sizing", which was accurate when we first drafted up the spec since it only addressed those topics. But now it hosts the full definition of all the sizing properties, so a rename is in order. I propose "CSS Box Sizing".

[rachelandrew]

Makes a lot of sense to me (and is also a lot easier to say on stage).

[css-meeting-bot]

The CSS Working Group just discussed Rename spec to CSS Box Sizing, and agreed to the following:

• RESOLVED: remane Box Intrinsic Sizing to Box Sizing with no change in shortname

The full IRC log of that discussion

<dael> Topic: Rename spec to CSS Box Sizing
<dael> github: https://github.com//issues/3962
<dael> fantasai: When we first drafted this spec it was limited but now it has all box sizing so should rename
<florian> +1
<dael> Rossen_: Reasonable. Other opinions?
<dael> AmeliaBR: No change to shortname?
<dael> fantasai: Still css-sizing
<dael> dbaron: A little worried about confusion with box sizing property.
<dael> fantasai: Which is in this spec
<dael> dbaron: But it's a lot more.
<dael> fantasai: Happy for other suggestions, but need to remove intrinsic and extrinsic from title
<dael> AmeliaBR: CSS sizing too general?
<dael> Rossen_: I think so
<dael> fantasai: Box Alignment and Box Sizing go together
<dael> Rossen_: I think box sizing is great. Point about confusion is well taken, but prop is in the spec. I don't think it will cause too much confusion
<dael> Rossen_: Unless there's better names lets resolve
<dael> Rossen_: Obj to remane Box Intrinisic Sizing to Box Sizing with no change in shortname?
<dael> RESOLVED: remane Box Intrinsic Sizing to Box Sizing with no change in shortname