Examine source code of GChat - Pin threads

{
  "manifest_version": 2,
  "name": "GChat - Pin threads",
  "description": "Pin your threads to use another time",
  "browser_action": {
    "default_icon": "./images/logo.png",
    "default_popup": "./popup/index.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://chat.google.com/*",
        "https://mail.google.com/chat/*"
      ],
      "all_frames": true,
      "js": [
        "./scripts/content.js"
      ],
      "css": [
        "./styles/styles.css"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "storage"
  ],
  "version": "1.0.5",
  "browser_specific_settings": {
    "gecko": {
      "id": "{4174bafb-f127-49b5-8db5-312503469f59}"
    }
  }
}