Examine source code of Twitter Focus

{
  "name": "Twitter Focus",
  "manifest_version": 2,
  "version": "0.2",
  "description": "A web extension that allows you to hide the feed and What's Happening panel on Twitter so you can focus and control your experience!",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "TwitterFocus"
  },
  "permissions": [
    "tabs"
  ],
  "content_scripts": [
    {
      "run_at": "document_end",
      "matches": [
        "*://*.twitter.com/*"
      ],
      "js": [
        "focus.js",
        "quotes.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "icon.png",
    "logo.png",
    "paypal.png",
    "github.svg",
    "github-dim-dark.svg",
    "linkedin.svg"
  ]
}