Examine source code of Transparent Image Maker

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "1.1",
  "description": "__MSG_extensionDescription__",
  "permissions": [
    "activeTab",
    "contextMenus",
    "storage",
    "notifications",
    "webRequest",
    "webRequestBlocking",
    "https://api.remove.bg/"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{14f47674-6ed3-472b-9d8f-3e668754f3ab}"
    }
  }
}