Examine source code of Quillbot

{
  "manifest_version": 2,
  "name": "Quillbot",
  "short_name": "Quillbot",
  "description": "Your smart thesaurus to sophistically restructure and reword sentences.",
  "version": "0.1.221resigned1",
  "minimum_chrome_version": "38",
  "permissions": [
    "contextMenus"
  ],
  "icons": {
    "16": "assets/icon-16.png",
    "48": "assets/icon-48.png",
    "128": "assets/icon-128.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "assets/icon.png"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+F",
        "mac": "MacCtrl+Shift+F"
      },
      "description": "Opens quillbox"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{72f9a34d-d4e0-49a6-8b9c-84b1e559f722}"
    }
  }
}