Kurt Eckhardt fc9159a681 T4.1 make SPI CS pins be index not mask, plus Franks change to timing The CS pins on T4.x are not like 3.x in that is you select one by index, not one or more by mask. So changed returned values to be index (1 based) Also while testing I pulled in Frank's change for adding delay after CS pin is logically selected.		pirms 4 gadiem
examples	Example setup code bug	pirms 7 gadiem
README.md	Update readme	pirms 10 gadiem
SPI.cpp	T4.1 make SPI CS pins be index not mask, plus Franks change to timing	pirms 4 gadiem
SPI.h	T4.1 make SPI CS pins be index not mask, plus Franks change to timing	pirms 4 gadiem
keywords.txt	Add SPI Buffer functions	pirms 7 gadiem
library.properties	Add library.properties	pirms 8 gadiem

SPI Library for Teensy