Examine source code of Save code to codeckin.com

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Save code to codeckin.com",
  "description": "Select code snippet, right click or click the extension icon to save it to codeckin.com",
  "version": "1.0.0",
  "homepage_url": "https://github.com/codeckincom/code-snippets-browser-extension",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "background": {
    "scripts": [
      "browser-polyfill.0.6.0.js",
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "browser_action": {
    "default_icon": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{25dfb373-78b2-46b4-8047-11fbed9577e7}"
    }
  }
}