Examine source code of halt-hammerzeit

{
  "description": "Adds a dedicated stop button to Firefox. Icons made by Freepik from www.flaticon.com",
  "manifest_version": 2,
  "author": "Daniel Suess",
  "name": "halt-hammerzeit",
  "homepage-url": "https://github.com/dseuss/halt-hammerzeit",
  "version": "0.2resigned1",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "64": "icons/icon-64.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ccbbd861-1a9d-4553-b2b7-a1e792b0cf3a}"
    }
  }
}