Correcting the markdown in the README.md
Correcting the markdown in the README.md

The markdown in the below sections of the README.md were not having the desired effect:
 * Introduction
 * Usage 
 * Testing

Corrected the sections so that the markdown has the desired effect
BillMills/AutoQC,IQuOD/AutoQC,s-good/AutoQC,IQuOD/AutoQC,BillMills/AutoQC,s-good/AutoQC,castelao/AutoQC