Improve internal keyevent names

internal/action/keytree.go

@@ -0,0 +1,12 @@
+package action
+
+type KeyAction func(Pane) bool
+type MouseAction func(Pane, *MouseEvent) bool
+type KeyAnyAction func(Pane, keys []KeyEvent)
+
+type KeyTreeNode struct {
+	children map[Event]KeyTreeNode
+
+	// action KeyAction
+	// any KeyAnyAction
+}