tmux: Require confirmation before killing a pane

It happened to me multiple times that I closed a pane without actually
wanting it via a (too) quick <C-d>.

Activate remain-on-exit so that I have to press <C-d> twice before the
pane is actually killed. Dead panes can be recovered with
`respawn-pane`.

Will see how this goes - could be annoying.

.config/tmux/tmux.conf

@@ -249,6 +249,10 @@ bind -r C-v command-prompt -k -p (selfinsert) { send "%%" }
 # Synchronize the panes in the current window with `<prefix>S`
 bind S set -w synchronize-panes
 
+# Require confirmation before killing a pane
+set -g remain-on-exit on
+bind -n C-d if -F "#{pane_dead}" { kill-pane } { send }
+
 # Change installation location of plugins
 setenv -g TMUX_PLUGIN_MANAGER_PATH "$XDG_CONFIG_HOME/tmux/plugins/"