Document PREPARE statements

[leoyvens]

DataFusion supports PREPARE statements, with flavors to suit all tastes such as explicit or inferred types, and positional or named arguments. I noticed docs for this feature are entirely missing from the SQL Reference (link).

[alamb]

Yes, thank you @leoyvens

@NGA-TRAN , @erratic-pattern and @jonahgao have done some great work in this area and indeed it would be great to get it documented