* Basic support of SIPO shift register
* typo
* add example of shiftregister for arduino and nucleo
* Fix build flag for nucleof103rb
* Fix wrong data pin configuration
* Change README.md for Shift registers
* Add API for individual register's output pin
* Rewrite shift register example to show ShiftPin usage
* Fix target for shiftregister example smoke test
* Fix type in makefile
* Add shiftregister compatble IC
* Edit comment and readme
Jean François CASSAN