update ReadMe.txt
update ReadMe.txt

add Jeff and Paul as developer of NPOI 2.0

tonyqus/npoi,xl1/npoi,vinod1988/npoi,stuartwmurray/npoi,antony-liu/npoi,tkalubi/npoi-1,jcridev/npoi,JesseQin/npoi,akrisiun/npoi,Yijtx/npoi