Examine source code of Anime Discord RPC

{
  "manifest_version": 2,
  "name": "Anime Discord RPC",
  "version": "1.1.1",
  "description": "Free and OpenSource Firefox AddOn, allows you to get a rich presence display in Discord when watching anime. Please note that launching Rich Presence from the browser requires another background application to work.",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://aniworld.to/*",
        "https://www.crunchyroll.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "webNavigation",
    "storage",
    "tabs",
    "webRequest",
    "http://127.0.0.1:8000/*"
  ],
  "browser_action": {
    "default_icon": "icons/logo-32.png",
    "default_title": "Test AddOn",
    "default_popup": "popup/popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1f26e356-1c37-476c-b2ea-c038e3f49bb3}"
    }
  }
}