Examine source code of doorsopen

{
  "manifest_version": 2,
  "name": "doorsopen",
  "description": "Calculates affordability and colour codes listings on Rightmove and Zoopla.",
  "version": "1.0",
  "license": "MIT",
  "author": "Shin Fujita (includes open-source code by joshembling joshembling@gmail.com available under MIT License)",
  "permissions": [
    "storage",
    "tabs",
    "https://zoopla.co.uk/*",
    "https://rightmove.co.uk/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_icon": "icon_purple.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.zoopla.co.uk/*",
        "https://www.rightmove.co.uk/*"
      ],
      "js": [
        "dist/bundle.js"
      ],
      "css": [
        "edit.css"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{2983c9dc-477b-493a-b4ac-fb96fa5a98bf}"
    }
  }
}