Docs for `SET` don't mention support for query parameters

ClickHouse's `SET` statement can be used to specify query parameters via the `param_` prefix, see [Syntax | ClickHouse Docs](https://clickhouse.com/docs/sql-reference/syntax#defining-and-using-query-parameters). This important feature is unfortunately not mentioned in the [very docs for the `SET` statement](https://clickhouse.com/docs/sql-reference/statements/set). 