Add Stage everything

[LDprg]

There is an unstage everything default shortcut, but no stage everything shortcut.
I would suggest adding stage everything with "S" as shortcut, since it would be consistent with unstage everything and isn't used elsewhere.

[tpope]

I copied U from Magit, which doesn't have a corresponding S map. And I can see why. What does "everything" mean? Does it include untracked files? There's no one correct way to stage all files.

[LDprg]

@tpope I thought a shortcut similar to "git add -A" since this is what you mostly want to do during normal development.
It just so there is no need to go over every entry and press 's' individually.
Or "git add -u" so only modified and deleted files are added.