tmux: Add `^w` as prefix2
tmux: Make sure to unbind `split` actions
tmux: Add toggles for last-{window,pane}
tmux: Shorten delay when typing “commands”
tmux: Add default `reattach-to-user-namespace`

Seems to resolve issues with copy / pasting.
tmux: Automatically set window title from app

I think this is enabled by default, but not really sure.
tmux: Configure window notifications

Or rather, monitor activity but don’t give me annoying messages that
something has changed, I can see that from the status bar.
tmux: New colour(s) for active pane
tmux: Colours for messages

Even though there shouldn’t really be any messages, if there are, then
have them stand out a bit.
tmux: Status bar customisation

All of the colours and things. Picked some bits here and there.