Examine source code of Facebook follow spam blocker

{
  "manifest_version": 2,
  "name": "Facebook Follow Spam Blocker",
  "version": "2.1",
  "description": "Automatically blocks Facebook posts with Follow suggestions",
  "browser_specific_settings": {
    "gecko": {
      "id": "fb-follow-hider@local",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "permissions": [
    "*://www.facebook.com/*",
    "*://facebook.com/*"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icon48.png"
    },
    "default_popup": "popup.html",
    "default_title": "Facebook Follow Spam Blocker"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.facebook.com/*",
        "*://facebook.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "96": "icon96.png",
    "128": "icon128.png"
  }
}