refactor: organize codes

src/electron/dockMenu.js

@@ -0,0 +1,25 @@
+const { Menu } = require("electron");
+
+export function createDockMenu(win) {
+  return Menu.buildFromTemplate([
+    {
+      label: "Play",
+      click() {
+        win.webContents.send("play");
+      },
+    },
+    { type: "separator" },
+    {
+      label: "Next",
+      click() {
+        win.webContents.send("next");
+      },
+    },
+    {
+      label: "Previous",
+      click() {
+        win.webContents.send("previous");
+      },
+    },
+  ]);
+}