Examine source code of JsonFormatter

{
  "name": "JsonFormatter",
  "description": "An easy way to format JSON",
  "version": "0.1",
  "manifest_version": 3,
  "permissions": [
    "contextMenus",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "jsonformatter@fayebuchanan",
      "strict_min_version": "42.0"
    }
  },
  "icons": {
    "32": "assets/icons/icon_32.png",
    "48": "assets/icons/icon_48.png",
    "64": "assets/icons/icon_64.png",
    "128": "assets/icons/icon_128.png"
  },
  "background": {
    "scripts": [
      "firefoxMain.js"
    ]
  }
}