Some Grid Layout shorthands are missing

[Destiner]

There's a block of grid-related rules, but some variants are missing. For example, there's grid-column-gap, grid-row-gap, and grid-gap, but no row-gap and gap, which are also valid.

[desjardinsm]

For some background information from MDN:

Note: When grid first shipped in browsers the column-gap, row-gap and gap were prefixed with the grid- prefix as grid-column-gap, grid-row-gap and grid-gap respectively.
Browsers all now support unprefixed values, however the prefixed versions will be maintained as aliases making them safe to use.

Also of note is that since gap (grid-gap) is shorthand for row-gap/column-gap, it should come before grid-column-gap (whereas currently grid-column-gap comes first).

Although as it stands, column-gap does exist, but grouped with the "Multi-column Layout" column properties.

Lastly, I'm looking for references in the spec or other docs for the following properties, but I can't find anything. Do you know what they are for?
"grid-after", "grid-before", "grid-columns", "grid-end", "grid-rows", "grid-start",

[Bielousov]

Upvote. gap is getting moved to the props end.