feat: allow null in keybindings

docs/Config.md

@@ -436,6 +436,8 @@ gui:
 
 For all possible keybinding options, check [Custom_Keybindings.md](https://github.com/jesseduffield/lazygit/blob/master/docs/keybindings/Custom_Keybindings.md)
 
+You can disable certain key bindings by specifying `null`.
+
 ### Example Keybindings For Colemak Users
 
 ```yaml

pkg/gui/keybindings/keybindings.go

@@ -179,6 +179,5 @@ func GetKey(key string) types.Key {
 	} else if runeCount == 1 {
 		return []rune(key)[0]
 	}
-	log.Fatal("Key empty for keybinding: " + strings.ToLower(key))
 	return nil
 }

pkg/gui/options_menu_panel.go

@@ -58,7 +58,7 @@ func (gui *Gui) handleCreateOptionsMenu() error {
 			OpensMenu: binding.OpensMenu,
 			Label:     binding.Description,
 			OnPress: func() error {
-				if binding.Key == nil {
+				if binding.Handler == nil {
 					return nil
 				}