Examine source code of AVIF MIME Fix

{
  "manifest_version": 2,
  "name": "AVIF MIME Fix",
  "version": "1.1",
  "description": "Fix wrong MIME type for .avif images",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5b33829d-7d3e-448e-a64c-afc7376804bf}"
    }
  }
}