The goal of this documentation is to help people that find code that uses these
classes, understand that the code is outdated and to refer them to the newer
template-based layout builder classes.
Change-Id: I4ba632be989686749181bdbc4e7f8a29adf01a5e
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2353
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>