Examine source code of MastoLink

{
  "manifest_version": 2,
  "name": "MastoLink",
  "author": "Filippo Dibenedetto",
  "version": "1.0.0",
  "description": "Capture a Mastodon post",
  "browser_specific_settings": {
    "gecko": {
      "id": "mastolink@dib21.it"
    }
  },
  "icons": {
    "48": "icon.svg",
    "96": "icon.svg"
  },
  "permissions": [
    "storage",
    "menus",
    "activeTab",
    "webNavigation",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  }
}