BREAKS CONFIG: rename 'level up' to 'focus parent'

…and 'level down' to 'focus child'. More intuitive than the old command names.

i3.config

@@ -40,8 +40,11 @@ bindsym Mod1+l layout default
 # toggle tiling / floating
 bindsym Mod1+Shift+space mode toggle
 
-bindsym Mod1+u level up
-#bindsym Mod1+d level down
+# focus the parent container
+bindsym Mod1+u focus parent
+
+# focus the child container
+#bindsym Mod1+d focus child
 
 # Kill current window
 bindsym Mod1+c kill