Examine source code of Remove Twitter Timeline

{
  "manifest_version": 2,
  "name": "Remove Twitter Timeline",
  "version": "0.1.1",
  "description": "Firefox add-on that removes the timeline on Twitter",
  "homepage_url": "https://github.com/vinayak-mehta/remove-twitter-timeline",
  "icons": {
    "48": "icons/logo-48.png",
    "96": "icons/logo-96.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "tabs",
    "activeTab",
    "*://twitter.com/*"
  ]
}