Changed installation documentation.
Changed installation documentation.

Removed "--reinstall" argument from installation command example. When it is
used it removes all vendors and downloads them again.

kuborgh/serializer,alexdesignworks/serializer,Nilead/serializer,mpoiriert/serializer,jms-serializer/serializer,j-arnaiz/serializer,progrupa/serializer,Soullivaneuh/serializer,curzio-della-santa/serializer,julienverrecchia/serializer,Avazanga1/Serializer,marcoleong/serializer,crazycodr/serializer,ahsanity/serializer,potherca-contrib/serializer,jockri/serializer,p-nowak/serializer,vslinko-forks/serializer,Klinche/serializer,leberknecht/serializer,megazoll/serializer,jmcclell/serializer,schmittjoh/serializer,nick4fake/serializer,sesch/serializer,thenetexperts/serializer,gkocakaya/serializer,scasei/serializer,zalatnaicsongor/serializer,ArteGEIE/serializer,tschreiner/serializer,brettminnie/serializer,marco-roy/serializer,Bluestart83/serializer,paali/serializer,sloba88/serializer,stof/serializer,nhaynes/serializer,goetas/serializer,apa-opensource/serializer