Examine source code of Mussol Extension

{
  "manifest_version": 2,
  "name": "Mussol Extension",
  "version": "1.9",
  "description": "Mussol Web Extension",
  "homepage_url": "https://app.antara.ws/mussol",
  "author": "Antara Information Technology s.l.",
  "developer": {
    "name": "Antara",
    "url": "https://www.antara.ws"
  },
  "icons": {
    "48": "assets/mussol-icon-op-48.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "unlimitedStorage",
    "notifications",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "vendor/browser-polyfill.min.js",
        "content_scripts/check_for_rss.js",
        "rss/rss-formatter.js"
      ]
    }
  ],
  "applications": {
    "gecko": {
      "id": "mussol@antara.ws"
    }
  },
  "browser_action": {
    "browser_style": false,
    "default_icon": "assets/mussol-icon-void-32.png",
    "default_title": "Mussol",
    "default_popup": "popup/menu_mussol.html"
  },
  "web_accessible_resources": [
    "assets/mussol-icon-op-32.png",
    "rss/rss.css",
    "rss/rss.xsl"
  ],
  "background": {
    "scripts": [
      "vendor/browser-polyfill.min.js",
      "background/script.js"
    ]
  },
  "options_ui": {
    "page": "options/page.html",
    "browser_style": true
  },
  "default_locale": "en"
}