Examine source code of Hide Game Feed Column

{
  "description": "Hides the right column where the game feed is displayed, providing a cleaner and less distracting interface",
  "manifest_version": 2,
  "name": "Hide Game Feed Column",
  "version": "1.0",
  "icons": {
    "48": "icons/border-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.facebook.com/*"
      ],
      "js": [
        "fb.js"
      ],
      "css": [
        "fb.css"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "*://*.facebook.com/*"
      ],
      "js": [
        "fb.js"
      ],
      "css": [
        "fb.css"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "*://*.facebook.com/*"
      ],
      "js": [
        "fb.js"
      ],
      "css": [
        "fb.css"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{6453cdf2-5fa9-4564-bf3c-4c9e6240445d}"
    }
  }
}