Examine source code of MindPane

{
  "browser_action": {
    "default_icon": {
      "16": "images/icon-16.png",
      "32": "images/icon-32.png",
      "48": "images/icon-48.png",
      "128": "images/icon-128.png"
    },
    "default_title": "Turns every web page into a Mind Map"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_security_policy": "script-src 'self' 'unsafe-inline' 'unsafe-eval'; object-src 'self'; sandbox allow-scripts allow-forms allow-popups allow-modals; child-src 'self';",
  "description": "Turns every web page into a Mind Map",
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAhpDzlWwXyt8oeCWuRhggiPls+x6EUCE4kt9H1YyJvY53gQakwdRAz2I4xTQ2an71ZucYc0bX33h/SVoIvYy2gxgW2o15E6J+jFdyPuuZElmGzRfGWPP+iPUzGLfAMAG7BfrtpMEcOJ9YOYeSBfV5CjSzw8xWxYZcJ6FcDHS66Y2Ca3NfesFFeiMvi5CyFyK3qq95pbQSHDqiZuD8Tpjh7nl0WTIUH17aw0aoCPxg988FTNmIU8U8e2wrJ/FY8FfbkSNQK8/19HBtcoJMPZaLbNTh2qECIECjtlTZRuvPDpRtsG5N8S6pnvWX8x7gVfwFNm0I0GuBPZzwO5tPw1j3awIDAQAB",
  "manifest_version": 2,
  "name": "MindPane",
  "permissions": [
    "tabs",
    "storage",
    "http://*/*",
    "https://*/*"
  ],
  "version": "1.3.0",
  "web_accessible_resources": [
    "images/icon-128.png",
    "images/icon-16.png",
    "images/icon-32.png",
    "images/icon-48.png",
    "scripts/mp_chrome/mp_chrome.nocache.js",
    "scripts/mp_chrome/commonmark/*.js",
    "scripts/mp_chrome/turndown/*.js",
    "scripts/mp_chrome/clear.cache.gif",
    "background.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ef1a403c-1afe-45c4-be5f-e4cb4cf9e729}"
    }
  }
}