Examine source code of Smart Link Expander

{
  "manifest_version": 2,
  "name": "Smart Link Expander",
  "version": "1.2.1",
  "permissions": [
    "storage",
    "contextMenus",
    "scripting",
    "clipboardWrite"
  ],
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "options_page": "options.html",
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e65a2441-92a2-4cd8-b41e-e96f1c799c39}"
    }
  }
}