Examine source code of Twitch Flags

{
  "manifest_version": 3,
  "name": "Twitch Flags",
  "version": "0.1.8",
  "description": "Shows resolved country flag emoji beside usernames in Twitch chat.",
  "icons": {
    "48": "icons/twitch-flags-48.png",
    "96": "icons/twitch-flags-96.png",
    "128": "icons/twitch-flags-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "twitch-flags@twitchflags.live",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "personallyIdentifyingInfo",
          "websiteContent"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "https://www.twitch.tv/*",
    "https://twitch.tv/*",
    "https://dashboard.twitch.tv/*",
    "https://twitchflags.live/*"
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "flags/*.svg"
      ],
      "matches": [
        "https://www.twitch.tv/*",
        "https://twitch.tv/*",
        "https://dashboard.twitch.tv/*"
      ]
    }
  ],
  "action": {
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.twitch.tv/*",
        "https://twitch.tv/*",
        "https://dashboard.twitch.tv/*"
      ],
      "js": [
        "bridge.js"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "world": "MAIN"
    },
    {
      "matches": [
        "https://www.twitch.tv/*",
        "https://twitch.tv/*",
        "https://dashboard.twitch.tv/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "world": "ISOLATED"
    }
  ]
}