Examine source code of VX Twitter

{
  "manifest_version": 2,
  "name": "VX Twitter",
  "version": "1.0",
  "description": "Minimal extension that adds 'vx' to the start of twitter urls when sharing. Also adds a ctrl+c hotkey to share the current tweet with 'vx' added if no text is selected.",
  "icons": {
    "48": "icons/48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.twitter.com/*"
      ],
      "js": [
        "script.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{50ad6d46-f109-4339-b052-b53f08ed8cca}"
    }
  }
}