Rework tmux dev setup spawning

Remove the unrequired -2 option when attaching a tmux session. Get rid
of the warning when selecting the window by providing the missing + and
remove the unrequired split-window.

scripts/startdevelop.sh

@@ -8,19 +8,17 @@ tmux new-session -d -s ${SESSION}
 
 # Setup panes
 tmux new-window -t ${SESSION}:0 -n "${SESSION}"
-tmux split-window -v
-tmux select-pane -t 0
 tmux send-keys "make js-watcher" C-m
+tmux split-window -v
 tmux select-pane -t 1
 tmux send-keys "make sass-watcher" C-m
 tmux split-window -v
 tmux select-pane -t 2
 tmux send-keys "caddy" C-m
 
-
 # Set default window
-tmux select-window -t $SESSION:1
+tmux select-window -t $SESSION:+1
 
 # Attach to session
-tmux -2 attach-session -t $SESSION
+tmux attach-session -t $SESSION