highlighting the limits around getting transactions metadata

at the moment there is no indication in the SQL server transaction metadata documentation (https://debezium.io/documentation/reference/connectors/sqlserver.html#sqlserver-transaction-metadata ) around the limits in fetching data.

In practice, Debezium will only register and receive transaction created after the component itself was deployed and no transactions before that.

I think it's worth mentioning because it is not clear from the documentation (in general regardless of the database)