Examine source code of Amazon Climate Filter

{
  "manifest_version": 2,
  "name": "Amazon Climate Filter",
  "version": "0.2.1",
  "description": "Filter Amazon Listings based on whether they are climate pledge friendly or not.",
  "developer": {
    "name": "Aidan Raney",
    "url": "https://devaidan.com/"
  },
  "author": "Aidan Raney",
  "homepage_url": "https://github.com/AidanSpeakss/amazon-shipping-filter",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "Amazon Climate Filter"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.amazon.com/*",
        "*://*.amazon.it/*",
        "*://*.amazon.es/*",
        "*://*.amazon.de/*",
        "*://*.amazon.co.uk/*",
        "*://*.amazon.fr/*"
      ],
      "js": [
        "amazon-shipping-filter.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{7f116826-1ede-4c3d-ae4b-7c71fe6e64be}"
    }
  }
}