feat: shift data when storing piso sr right away

chore: add Makefile for easier testing

tests: add tests for spi recv and transmit

tests: add tests for shift registers

feat: add spi transmit and receive

chore: add vunit run configuration python file

chore: add caches to gitignore

fixup! feat: add shift registers

feat: add shift registers

feat: add Makefile template

Initial empty commit