Examine source code of 2bed

{
  "manifest_version": 2,
  "name": "2bed",
  "version": "0.1.2",
  "description": "Sends you to bed by making the experience on time-wasting web sites just annoying enough to be unenjoyable after bedtime. Hold the mouse button without moving at all to escape the bed.",
  "icons": {
    "48": "bed.svg",
    "96": "bed.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.reddit.com/*",
        "*://news.ycombinator.com/*",
        "*://*.youtube.com/*"
      ],
      "js": [
        "bed.js"
      ]
    }
  ]
}