feat: add menu link to source code

src/intro.js

@@ -5,6 +5,13 @@ const _GM = typeof GM == 'object' ? GM : undefined;
 const gmId = '' + Math.random();
 w[gmId] = _GM;
 
+if (_GM && _GM.registerMenuCommand && _GM.openInTab) {
+  // add buttons to the userscript manager menu
+  _GM.registerMenuCommand(
+    '** Source Code **',
+    () => _GM.openInTab(_GM.info.script.homepage, { active: true })
+  )
+}
 
 // script loader
 new Promise(resolve => {

src/meta.js

@@ -15,5 +15,6 @@
 // @grant        unsafeWindow
 // @grant        GM.registerMenuCommand
 // @grant        GM.addElement
+// @grant        GM.openInTab
 // @run-at       document-start
 // ==/UserScript==