Examine source code of ContentEditable

{
  "manifest_version": 2,
  "name": "__MSG_name__",
  "description": "__MSG_desc__",
  "version": "1.1.0",
  "homepage_url": "https://github.com/pepelsbey/contenteditable",
  "default_locale": "en",
  "icons": {
    "16": "images/icon-16.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "page_action": {
    "default_icon": {
      "19": "images/button-19.png",
      "38": "images/button-38.png"
    },
    "default_title": "__MSG_enable__"
  },
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f560455e-2f5b-44aa-87c8-7ae54f14be64}"
    }
  }
}