Examine source code of Reimagined Scratch

{
  "name": "Reimagined Scratch",
  "version": "0.1.3",
  "description": "Improves the Scratch interface",
  "homepage_url": "https://github.com/MasterOfTheTiger/reimagine-scratch",
  "manifest_version": 2,
  "permissions": [
    "https://scratch.mit.edu/*"
  ],
  "content_scripts": [
    {
      "run_at": "document_start",
      "matches": [
        "https://scratch.mit.edu/*"
      ],
      "css": [
        "content.css"
      ],
      "js": [
        "content.js"
      ]
    },
    {
      "run_at": "document_start",
      "matches": [
        "https://scratch.mit.edu/",
        "https://scratch.mit.edu/messages"
      ],
      "css": [
        "justnew.css"
      ],
      "js": [
        "justnew.js"
      ]
    }
  ]
}