Examine source code of BOE Comparador

{
  "manifest_version": 2,
  "name": "BOE_Comparador",
  "version": "1.0.5",
  "description": "Extensión No Oficial para comparar modificaciones legales publicadas en el Boletín Oficial del Estado (BOE).",
  "action": {
    "default_icon": {
      "16": "/images/BOE-16.png",
      "32": "/images/BOE-32.png",
      "48": "/images/BOE-48.png",
      "128": "/images/BOE-128.png"
    },
    "default_title": "Proyecto BOE Comparador",
    "default_popup": "git_popup.html"
  },
  "icons": {
    "16": "/images/BOE-16.png",
    "32": "/images/BOE-32.png",
    "48": "/images/BOE-48.png",
    "128": "/images/BOE-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.boe.es/*"
      ],
      "js": [
        "contentScript.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{97a2465b-298d-40ae-8922-740e2e134e8f}"
    }
  }
}