nit: add prdoc for 3370 (#3401)
Did not realize that
https://github.com/paritytech/polkadot-sdk/pull/3370 was indeed
breaking. cc @muraca
---------
Signed-off-by: 
Oliver Tale-Yazdi <[email protected]>
Did not realize that
https://github.com/paritytech/polkadot-sdk/pull/3370 was indeed
breaking. cc @muraca
---------
Signed-off-by: Oliver Tale-Yazdi <[email protected]>