WASM Client Add DuckDBQueryConfig example

[bluehat974]

https://duckdb.org/docs/archive/0.9.1/api/wasm/instantiation

Add example to explain the following options from DuckDBQueryConfig:

• castBigIntToDouble
• castDecimalToDouble
• castDurationToTime64
• castTimestampToDate
• queryPollingInterval

await this._db.instantiate(bundle.mainModule, bundle.pthreadWorker)
    await this._db.open({
      path: ':memory:',
      query: {
        castBigIntToDouble: true,
        castDecimalToDouble: true,
        castDurationToTime64: true,
        castTimestampToDate: true,
        queryPollingInterval: 1000,
      },
    })