Examine source code of AddAccents

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "short_name": "__MSG_extensionNameShort__",
  "version": "0.3",
  "author": "Jean Laroche",
  "description": "__MSG_extensionDescription__",
  "homepage_url": "https://github.com/jeanlaroche/AddAccentsExtension",
  "options_ui": {
    "page": "options/options.html",
    "browser_style": true
  },
  "background": {
    "page": "background/background.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "all_frames": true,
      "match_about_blank": true,
      "js": [
        "content_scripts/insert_accents.js"
      ]
    }
  ],
  "content_security_policy": "default-src 'self'",
  "default_locale": "en",
  "permissions": [
    "storage",
    "tabs",
    "compose",
    "menus"
  ],
  "applications": {
    "gecko": {
      "id": "addAccent@jeanlaroche.github.io",
      "strict_min_version": "87.0"
    }
  }
}