Examine source code of XML Viewer Plus

{
  "manifest_version": 2,
  "name": "XML Viewer Plus",
  "version": "1.2.6",
  "description": "A powerful XML Viewer, supports text/regex and jQuery/CSS, XPath selectors",
  "icons": {
    "16": "icons/logo-16.png",
    "48": "icons/logo-48.png",
    "128": "icons/logo-128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "applications": {
    "gecko": {
      "id": "@xmlformatter",
      "strict_min_version": "57.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "lib/saferInnerHTML.js",
        "content.js"
      ]
    }
  ],
  "permissions": [
    "<all_urls>",
    "webRequest",
    "webRequestBlocking",
    "contextMenus"
  ],
  "web_accessible_resources": [
    "css/content.css"
  ]
}