Examine source code of Enhancer for Nebula

{
  "manifest_version": 2,
  "name": "__MSG_title__",
  "description": "__MSG_extensionDescription__",
  "version": "1.7.6",
  "icons": {
    "64": "icons/icon_64.png",
    "128": "icons/icon_128.png"
  },
  "background": {
    "scripts": [
      "scripts/background_script.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.nebula.app/*",
        "*://*.nebula.tv/*",
        "*://*.youtube.com/*"
      ],
      "js": [
        "scripts/content_script.js"
      ],
      "css": [
        "styles/content.css"
      ],
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    "scripts/player.js",
    "scripts/youtube-helpers.js"
  ],
  "permissions": [
    "storage",
    "*://content.api.nebula.app/*",
    "*://*.nebula.tv/*"
  ],
  "optional_permissions": [
    "*://*.googleapis.com/*",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": {
      "64": "icons/icon_64.png",
      "128": "icons/icon_128.png"
    },
    "default_title": "__MSG_title__"
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true,
    "chrome_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "nebula-enhancer@piber.at"
    }
  },
  "default_locale": "en"
}