Examine source code of Dusky Gray Facebook [Dark Theme]

{
  "manifest_version": 2,
  "name": "Dusky Gray Facebook [Dark Theme]",
  "author": "pierO'n Mu",
  "description": "__MSG_extensionDescription__",
  "version": "2.1.1",
  "default_locale": "en",
  "icons": {
    "16": "icons/16.png",
    "19": "icons/19.png",
    "32": "icons/32.png",
    "38": "icons/38.png",
    "64": "icons/64.png",
    "128": "icons/128.png",
    "256": "icons/256.png"
  },
  "homepage_url": "http://pieroandmu.com/dusky-gray-addon",
  "browser_action": {
    "default_icon": {
      "16": "icons/16.png",
      "19": "icons/19.png",
      "32": "icons/32.png",
      "38": "icons/38.png",
      "64": "icons/64.png",
      "128": "icons/128.png",
      "256": "icons/256.png"
    },
    "default_title": "Dusky Gray Facebook [Dark Theme]",
    "default_popup": "popup/popup.html"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "idle"
  ],
  "background": {
    "scripts": [
      "dusky-gray-facebook-dark-theme.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.facebook.com/*",
        "*://*.facebookcorewwwi.onion/*",
        "*://*.messenger.com/*"
      ],
      "exclude_globs": [
        "*://*.facebook.com/help*",
        "*://*.facebook.com/Fplugins*",
        "*://*.facebook.com/plugins/like*",
        "*://*.facebook.com/events_manager*",
        "*://*.facebook.com/ads*",
        "*://*.facebook.com/about/ads*",
        "*://*.facebook.com/analytics*",
        "*://*.facebook.com/business*",
        "*://*.facebook.com/*plugins*",
        "*://developers.facebook.com/*",
        "*://work.facebook.com/*",
        "*://business.facebook.com/*"
      ],
      "js": [
        "dusky-gray-facebook-dark-theme.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    "dusky-gray-facebook-dark-theme.css"
  ]
}