[libcxx][docs] Update the One Ranges PRoposal Status with open revisions.

1. Moves the names into the names column.
2. Changes the names to reflect who's actually working on what.
3. Adds open revisions.

GitOrigin-RevId: 3ac9ff5577f1d4b032a64aea1c46e95c8a5b8f68
1 file changed