Examine source code of ClosReplace

{
  "manifest_version": 2,
  "name": "ClosReplace",
  "author": "nytpu",
  "version": "0.5.7",
  "description": "Beta! Bolds all instances of Clos in a webpage, can replace words with Clos.",
  "homepage_url": "https://github.com/RAND-bytes/ClosReplace",
  "icons": {
    "48": "icons/logo-48.png",
    "96": "icons/logo-96.png",
    "128": "icons/logo-128.png"
  },
  "permissions": [
    "storage",
    "tabs",
    "activeTab",
    "<all_urls>"
  ],
  "options_ui": {
    "page": "options.html"
  },
  "background": {
    "scripts": [
      "browser-polyfill.min.js",
      "background.js"
    ]
  },
  "applications": {
    "gecko": {
      "id": "closreplace@mrclos.com"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "browser-polyfill.min.js",
        "findAndReplaceDOMText.js",
        "replacer.js"
      ],
      "all_frames": true,
      "run_at": "document_idle"
    }
  ]
}