chore: update README
chore: update toolchain project
chore: add license
add_subdirectory in CMakeLists.txt to add this libraryavr_target_link_libraries(<executable-name> avr_shift_registers)simavr subfoldersimavr project using cmake. After running cmake
make sim_simavr_shift_registers to start simavrmake gdb_simavr_shift_registers to start simavr along with avr-gdb