Examine source code of Chess2

{
  "manifest_version": 3,
  "name": "Chess2",
  "version": "1.0",
  "description": "Bring the rules of Chess 2 to your favorite chess platform!",
  "icons": {
    "16": "chess2logo.png",
    "48": "chess2logo.png",
    "128": "chess2logo.png"
  },
  "permissions": [
    "declarativeNetRequest"
  ],
  "host_permissions": [
    "*://www.chess.com/*",
    "*://lichess.org/*"
  ],
  "declarative_net_request": {
    "rule_resources": [
      {
        "id": "redirect_rules",
        "enabled": true,
        "path": "rules.json",
        "comment": "You can disable this behavior by disabling the extension for chess.c*m in the settings"
      }
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://lichess.org/*"
      ],
      "js": [
        "lichess_shared.js"
      ]
    },
    {
      "matches": [
        "https://lichess.org/*"
      ],
      "js": [
        "lichess_chat_script.js"
      ]
    },
    {
      "matches": [
        "https://lichess.org/*"
      ],
      "js": [
        "lichess_moves_script.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "chess2@dakopen.de",
      "strict_min_version": "58.0"
    }
  }
}