Examine source code of Font blocker foxified

{
  "name": "Font blocker foxified",
  "description": "Blocks the fonts you want to block.",
  "version": "1.16.20",
  "permissions": [
    "storage",
    "contextMenus",
    "<all_urls>"
  ],
  "optional_permissions": [
    "*://developer.mozilla.org/*"
  ],
  "options_ui": {
    "open_in_tab": true,
    "page": "options/options.html"
  },
  "content_scripts": [
    {
      "all_frames": true,
      "js": [
        "fontblocker.logic.js",
        "fontblocker.content.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*",
        "file://*/*"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "fontblocker.logic.js",
      "fontblocker.background.js"
    ]
  },
  "page_action": {
    "default_title": "Font blocker foxified - (Un)glimpse blocked fonts",
    "default_icon": {
      "128": "images/128x128.png"
    }
  },
  "icons": {
    "128": "images/128x128.png"
  },
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "knpgaobajhnhgkhhoopjepghknapnikl@chrome-store-foxified-3903688695"
    }
  }
}