Add "afk" function to lock screen.

dotfiles/zshrc.d/afk.zsh

@@ -0,0 +1,11 @@
+function afk {
+  # Note, may fail if multiple users are logged in with different desktop
+  # environments.
+  if pidof cinnamon-screensaver >/dev/null ; then
+    cinnamon-screensaver-command -l
+  elif pidof gnome-screensaver >/dev/null ; then
+    gnome-screensaver-command -l
+  else
+    echo 'No screensaver found...' >&2
+  fi
+}