To contribute to the buildings, drag the file block_data.json and the converter.py to the buildings folder en double click on the converter.py to run the program. The program will try to create all the different files, but not all the block ids are in it. So the program will prompt the id of the block. You then need to enter the modern block id, for example 0:0 is now minecraft:air. After that the program will ask if this block id has an specific blockstate for example with a oak log new, the new id is minecraft:oak_log and it has as possible blockdata key the name axis and the possible values of axis are x, y or z.

Good luck with the converting