Examine source code of OGS Helper

{
  "browser_specific_settings": {
    "gecko": {
      "id": "ogs-helper@sharafian.com",
      "strict_min_version": "42.0"
    }
  },
  "background": {
    "scripts": [
      "background/index.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "128": "img/icon128.png"
    },
    "default_title": "OGS Helper",
    "default_popup": "options/index.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://online-go.com/*"
      ],
      "js": [
        "browser-polyfill.min.js",
        "content/index.js"
      ],
      "css": [
        "content/ogs-helper.css"
      ]
    }
  ],
  "description": "Add features to https://online-go.com to discourage bad habits",
  "icons": {
    "128": "img/icon128.png"
  },
  "options_ui": {
    "page": "options/index.html"
  },
  "manifest_version": 2,
  "name": "OGS Helper",
  "permissions": [
    "storage",
    "https://online-go.com/"
  ],
  "version": "0.5"
}