Add tmux aliases

Signed-off-by: Michael Barton <mail@michaelbarton.me.uk>
Reverse tmux window splitting

Signed-off-by: Michael Barton <mail@michaelbarton.me.uk>
Add tmux window options

Signed-off-by: Michael Barton <mail@michaelbarton.me.uk>
Add syntax for GHI files

Signed-off-by: Michael Barton <mail@michaelbarton.me.uk>