Add shell insert commands to typable and config

[Termina94]

• Add insert-output and append-output to allow for usage within command list as-well-as config files

This will allow for the example below where I am trying to create a syntax-highlighted git diff command

G = [ 
  ":open ~/.config/helix/temp.diff",
  "select_all",
  "delete_selection",
  ":append-output git diff"
]

[archseer]

Thanks!