Deselect action

[Arnaudv6]

I'm prepending 'Deselect' action to esc binding chain-of-actions.
Even though 'Deselect' action is not documented. Like this:

"Esc": "Deselect|UnhighlightSearch|RemoveAllMultiCursors|Escape",

I'd suggest we add this to the documentation, if you're OK with this. Should we take the opportunity to change https://github.com/zyedidia/micro/blob/master/internal/action/actions.go#L1523 as bellow, according to PR 2395?

h.Cursor.Deselect(buffer.ResetLocationDefault)

[niten94]

There is at least this pull request now where Deselect is added in keybindings.md: #3124