Examine source code of seenthis search

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "0.3.2",
  "homepage_url": "https://github.com/seenthis/firefox-seenthis-search",
  "icons": {
    "48": "icons/seenthis-48.png"
  },
  "applications": {
    "gecko": {
      "id": "seenthis_search@seenthis.net",
      "strict_min_version": "57.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/seenthis.svg"
  },
  "commands": {
    "openview": {
      "suggested_key": {
        "default": "Alt+S"
      },
      "description": "Open seenthis search"
    }
  },
  "options_ui": {
    "page": "content/options.html"
  },
  "permissions": [
    "*://seenthis.net/*",
    "storage"
  ],
  "default_locale": "fr"
}