Fix AssemblyVersion update instructions (#32200)
Fix AssemblyVersion update instructions (#32200)

* Fix AssemblyVersion update instructions

* Add documentation for editing packageIndex.json

wtgodbe/corefx,wtgodbe/corefx,ViktorHofer/corefx,wtgodbe/corefx,ViktorHofer/corefx,Jiayili1/corefx,BrennanConroy/corefx,ptoonen/corefx,shimingsg/corefx,Jiayili1/corefx,mmitche/corefx,wtgodbe/corefx,shimingsg/corefx,shimingsg/corefx,mmitche/corefx,mmitche/corefx,ptoonen/corefx,Jiayili1/corefx,ptoonen/corefx,ptoonen/corefx,mmitche/corefx,Jiayili1/corefx,ericstj/corefx,shimingsg/corefx,Jiayili1/corefx,ViktorHofer/corefx,ericstj/corefx,ericstj/corefx,ViktorHofer/corefx,BrennanConroy/corefx,ptoonen/corefx,ericstj/corefx,ViktorHofer/corefx,wtgodbe/corefx,ViktorHofer/corefx,ViktorHofer/corefx,mmitche/corefx,shimingsg/corefx,ericstj/corefx,mmitche/corefx,Jiayili1/corefx,ericstj/corefx,mmitche/corefx,ptoonen/corefx,BrennanConroy/corefx,shimingsg/corefx,shimingsg/corefx,ptoonen/corefx,wtgodbe/corefx,wtgodbe/corefx,ericstj/corefx,Jiayili1/corefx