Binding modes/binding submaps

[YaLTeR]

The ability to configure multiple binding modes with separate binds.

An example use-case is a "launcher" mode, where e.g. you press Super+D, then instead of the normal binds, you have binds to run applications, like F for firefox, N for nautilus, T for terminal, etc. So you press Super+D+F to run firefox.

There's a WIP implementation for binding modes: #532. The author's GitHub account had disappeared, but I remember about the PR and will get to it at some point.

[mastoca]

xmonad's approach for subkeys is interesting which I used in many ways. for example I use it to bring up the gridSelect module

       ...
        ^++^ subKeys
          "Grid Select (Super-g followed by a key)"
          [ ("M1-g g", addName "grid select some bookmarks" $ spawnSelected' myBookmarkGrid),
     ...