Examine source code of JLPT Copy Assistant

{
  "manifest_version": 2,
  "name": "JLPT Copy Assistant",
  "version": "1.2.0",
  "description": "Select and copy canvas regions on JLPT sample pages to clipboard",
  "permissions": [
    "activeTab",
    "clipboardWrite",
    "*://*.jlpt.jp/e/samples/*"
  ],
  "browser_action": {
    "default_title": "Select Canvas Region",
    "default_icon": {
      "16": "icon-16.png",
      "32": "icon-32.png",
      "48": "icon-48.png",
      "128": "icon-128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.jlpt.jp/e/samples/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{30f40fbb-4dac-4d56-bbf5-6bada80b19c9}"
    }
  }
}