…e size, but doesn't resize down. I also had to remove the seperator. I think I need to have the resize event start from the top, then recurse down

  * Works for both vertical and horizontal splits
  * seperator is visible too
  * resizing the window works right

  If you add keybindings for resizing, like so:
  ```json
            {
                "command" : "resizePaneDown",
                "keys" :
                [
                    "alt+shift+down"
                ]
            },
            {
                "command" : "resizePaneLeft",
                "keys" :
                [
                    "alt+shift+left"
                ]
            },
            {
                "command" : "resizePaneRight",
                "keys" :
                [
                    "alt+shift+right"
                ]
            },
            {
                "command" : "resizePaneUp",
                "keys" :
                [
                    "alt+shift+up"
                ]
            },

  ```

  Then you can now resize the panes, 5% at a time.

  We correctly traverse the tree to find the separator that's closest to the
  focused pane (depth-wise), but also the correct direction.

  I need the padding fix however

…sizable-panes

# Conflicts:
#	src/cascadia/TerminalApp/AppKeyBindings.cpp
#	src/cascadia/TerminalApp/AppKeyBindings.h
#	src/cascadia/TerminalApp/AppKeyBindingsSerialization.cpp

  But that might always have been broken

  Also add comments

…sizable-panes

…sizable-panes

# Conflicts:
#	src/cascadia/TerminalApp/App.cpp

…sizable-panes

# Conflicts:
#	src/cascadia/TerminalApp/App.cpp