[css-scroll-snap] Rename keywords 'proximity' and 'mandatory'

Both values are relatively long and one is a noun while the other is
an adjective, which makes them inconsistent.

Therefore I believe they should be renamed. The words I have in mind
are 'near' and 'always'. Though maybe somebody else can come up with
better words.

Sebastian

Received on Sunday, 13 December 2015 21:40:25 UTC