Examine source code of Special L10n

{
  "manifest_version": 2,
  "name": "Special L10n",
  "version": "4.0",
  "description": "Permite seleccionar caracteres especiales que utilizaran los usuarios que traducen Firefox en lenguas nativas (L10n) en Pontoon",
  "icons": {
    "48": "icons/special-48.png",
    "96": "icons/special-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.pontoon.mozilla.org/*"
      ],
      "js": [
        "special.js"
      ],
      "css": [
        "style.css"
      ]
    }
  ]
}