Examine source code of ProtonDB for Steam

{
  "manifest_version": 3,
  "version": "1.6.4",
  "name": "ProtonDB for Steam",
  "description": "Adds the ProtonDB rating to games in the Steam store so you get an idea of how it will run before you buy it!",
  "host_permissions": [
    "https://www.protondb.com/*"
  ],
  "permissions": [
    "storage"
  ],
  "icons": {
    "16": "/icons/proton_16.png",
    "32": "/icons/proton_32.png",
    "48": "/icons/proton_48.png",
    "128": "/icons/proton_128.png"
  },
  "action": {
    "default_popup": "html/options.html"
  },
  "options_ui": {
    "page": "html/options.html",
    "open_in_tab": true
  },
  "background": {
    "service_worker": "js/background.js",
    "scripts": [
      "js/utils.js",
      "js/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://store.steampowered.com/*"
      ],
      "js": [
        "js/utils.js",
        "js/deck.js",
        "js/proton.js",
        "js/steamGeneral.js"
      ],
      "css": [
        "css/protondbCard.css",
        "css/variables.css"
      ]
    },
    {
      "matches": [
        "https://store.steampowered.com/app/*"
      ],
      "js": [
        "js/steamStore.js"
      ]
    },
    {
      "matches": [
        "https://store.steampowered.com/search*"
      ],
      "js": [
        "js/steamSearch.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{09d1226f-0dd0-4ad7-8a0f-cca316ea271e}",
      "strict_min_version": "101.0"
    }
  }
}