tmux: Improve kill keybinds and pervent tmux from closing when there are still sessions

tmux/dot-tmux.conf

@@ -11,6 +11,8 @@ set -sg escape-time 0
 
 set -g history-limit 5000
 
+set -g detach-on-destroy off  # don't exit from tmux when closing a session
+
 # Setup vi-mode with better keybindings
 # TODO: Escape does not work properly for leaving
 setw -g mode-keys vi
@@ -75,3 +77,6 @@ bind-key -n M-9 select-window -t 9
 bind-key -n M-0 select-window -t 10
 
 bind-key "a" run-shell "sesh-select"
+
+bind-key x kill-pane
+bind-key X kill-session