Examine source code of Keyboard Recorder

{
  "manifest_version": 2,
  "name": "Keyboard Recorder",
  "version": "1.1",
  "description": "Copia en el portapapeles lo que vayas a escribir a continuación desde que ejecutes el atajo Ctrl + 0.",
  "permissions": [
    "clipboardWrite",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "48": "icons/keyboard_recorder-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6b42708e-02b9-46cc-bcd1-11dc9e0b195f}"
    }
  }
}