Examine source code of Copy Numbers

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "1.0",
  "default_locale": "en",
  "homepage_url": "https://addons.mozilla.org/en-US/firefox/user/16308671/",
  "author": "Pieter Maes",
  "icons": {
    "16": "image/icon16.png",
    "32": "image/icon32.png",
    "48": "image/icon48.png",
    "64": "image/icon64.png",
    "128": "image/icon128.png"
  },
  "background": {
    "scripts": [
      "content/pref.js",
      "content/background.js"
    ]
  },
  "options_ui": {
    "page": "content/options.html",
    "open_in_tab": true,
    "browser_style": true
  },
  "permissions": [
    "activeTab",
    "clipboardRead",
    "clipboardWrite",
    "menus",
    "notifications",
    "storage"
  ],
  "commands": {
    "save": {
      "suggested_key": {
        "default": "F7"
      }
    },
    "save2": {
      "suggested_key": {
        "default": "Ctrl+Shift+F7"
      }
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "pieter.maes@gmail.com",
      "strict_min_version": "63.0"
    }
  }
}