add contributing section to readme
add contributing section to readme

saulide/testGit,isabanin/grit,suoqiangqiang/demofirst,brynary/grit,Max1mov/grit,Smvel/test,lyk4411/test,wykeham/tr2,suoqiangqiang/demofirst,wenwj/111,wwjun110/grit,mtinet/grit,HrishikeshSingh/testmodulerepo,thommay/grit,qijianbo/hub,guagualvcha/ticgit,gitcafe-dev/grit,gitcafe-dev/grit,jinmm1992/hope,WOODDREAM/try,qijianbo/hub,WOODDREAM/try,mtinet/grit,saulide/testGit,rgroux/grit,redronin/grit,Arjunduggal88/first,lyk4411/test,wlacawy/test,sburenko86/grit,VasiliyGryaznoy/test,shark12345/abc,RyantChan/testweb,feistar/RepoLearning,patientslikeme/grit,jecotany/test,rmendez1972/grit,yqb95/mygrit,shark12345/abc,wykeham/tr2,shark12345/mygit,jvirguezss/SS-DEVSS,gitlabhq/grit,wwjun110/grit,renatoramiro/grit,andreystadnik/testrepo,bpug/test,abicky/grit,flycutter/grit,riyad/grit,rmendez1972/grit,moodmass/grit,VasiliyGryaznoy/test,flycutter/grit,kevinsawicki/grit,jecotany/test,brynary/grit,shaomengchao/pb,isabanin/grit,shark12345/mygit,mojombo/grit,duanjun/test,sebastian-schulze/grit,adamlerer/grit,lucianmanciu/MyGrit,github/grit,enosje/Teste,KimGeoNam/geonam,Philipp1899/test_project,ManojkumarMenon/grit,enosje/Teste,schacon/grit,Max1mov/grit,nickle-ye/my_grit,izcms/testgit,HrishikeshSingh/testmodulerepo,rgroux/grit,pravinvanmore/restserver,izcms/testgit,wuligit/test1,WOODDREAM/try,Smvel/test,thommay/grit,eciuca/first-repo,jegj/Grit,gitlabhq/grit,JessRudder/grit,wenwj/111,kevinsawicki/grit,METROSTATE/mygrit,KimGeoNam/geonam,ckw1375/test,AkiraHash/grit,wwjun110/grit,user45/grit,JoeMburu/mygrits,xiaodie/example