Examine source code of Shush

{
  "manifest_version": 2,
  "name": "Shush",
  "version": "2.0",
  "description": "Remove the LinkedIn feed",
  "icons": {
    "48": "icons/border-48.png",
    "96": "icons/border-96.png"
  },
  "content_scripts": [
    {
      "all_frames": true,
      "css": [
        "shush.css"
      ],
      "run_at": "document_idle",
      "matches": [
        "*://*.linkedin.com/*"
      ]
    }
  ]
}