Examine source code of Discogs Tempo Adjust

{
  "manifest_version": 3,
  "name": "Discogs Tempo Adjust",
  "description": "A browser extension to adjust track tempo on Discogs",
  "version": "0.1.3",
  "icons": {
    "16": "icon-16.png",
    "128": "icon-128.png"
  },
  "action": {},
  "browser_specific_settings": {
    "gecko": {
      "id": "{6fc0284b-f220-4709-acad-d8b95f55637f}"
    }
  },
  "background": {
    "type": "module",
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.discogs.com/*"
      ],
      "css": [
        "content-scripts/discogs.css"
      ],
      "js": [
        "content-scripts/discogs.js"
      ]
    },
    {
      "matches": [
        "https://*.youtube-nocookie.com/*",
        "https://*.youtube.com/*"
      ],
      "all_frames": true,
      "js": [
        "content-scripts/youtube.js"
      ]
    }
  ]
}