Update GitHub links in README.md
Update GitHub links in README.md

Geod24/dub,Flamaros/dub,xentec/dub,y12uc231/dub,jeanbaptistelab/dub,D-Programming-Language/dub,rjframe/dub,dreamsxin/dub,nazriel/dub,Abscissa/dub,Abscissa/dub-data-mod,p0nce/dub,schuetzm/dub,grogancolin/dub,alexeibs/dub,jelmansouri/dub,gedaiu/dub