Add doc describing ref-reassignment (#24352)
Add doc describing ref-reassignment (#24352)


shyamnamboodiripad/roslyn,jcouv/roslyn,MichalStrehovsky/roslyn,AlekseyTs/roslyn,DustinCampbell/roslyn,dpoeschl/roslyn,genlu/roslyn,KirillOsenkov/roslyn,sharwell/roslyn,wvdd007/roslyn,AmadeusW/roslyn,xasx/roslyn,gafter/roslyn,davkean/roslyn,heejaechang/roslyn,mgoertz-msft/roslyn,Giftednewt/roslyn,jamesqo/roslyn,agocke/roslyn,tmeschter/roslyn,OmarTawfik/roslyn,KevinRansom/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,tannergooding/roslyn,dpoeschl/roslyn,VSadov/roslyn,mavasani/roslyn,genlu/roslyn,jasonmalinowski/roslyn,eriawan/roslyn,genlu/roslyn,panopticoncentral/roslyn,sharwell/roslyn,stephentoub/roslyn,bkoelman/roslyn,jamesqo/roslyn,tmat/roslyn,brettfo/roslyn,cston/roslyn,weltkante/roslyn,agocke/roslyn,ErikSchierboom/roslyn,stephentoub/roslyn,paulvanbrenk/roslyn,dpoeschl/roslyn,AlekseyTs/roslyn,mattscheffer/roslyn,reaction1989/roslyn,abock/roslyn,brettfo/roslyn,gafter/roslyn,nguerrera/roslyn,aelij/roslyn,abock/roslyn,nguerrera/roslyn,agocke/roslyn,DustinCampbell/roslyn,aelij/roslyn,heejaechang/roslyn,jamesqo/roslyn,Giftednewt/roslyn,ErikSchierboom/roslyn,diryboy/roslyn,tmat/roslyn,physhi/roslyn,nguerrera/roslyn,aelij/roslyn,jmarolf/roslyn,cston/roslyn,reaction1989/roslyn,gafter/roslyn,dotnet/roslyn,wvdd007/roslyn,mgoertz-msft/roslyn,physhi/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,VSadov/roslyn,cston/roslyn,stephentoub/roslyn,dotnet/roslyn,KirillOsenkov/roslyn,CyrusNajmabadi/roslyn,panopticoncentral/roslyn,AlekseyTs/roslyn,mavasani/roslyn,physhi/roslyn,reaction1989/roslyn,xasx/roslyn,davkean/roslyn,wvdd007/roslyn,tmat/roslyn,jcouv/roslyn,AmadeusW/roslyn,paulvanbrenk/roslyn,mattscheffer/roslyn,jcouv/roslyn,eriawan/roslyn,mavasani/roslyn,Giftednewt/roslyn,OmarTawfik/roslyn,CyrusNajmabadi/roslyn,paulvanbrenk/roslyn,jasonmalinowski/roslyn,KevinRansom/roslyn,davkean/roslyn,swaroop-sridhar/roslyn,swaroop-sridhar/roslyn,weltkante/roslyn,diryboy/roslyn,MichalStrehovsky/roslyn,diryboy/roslyn,tannergooding/roslyn,KirillOsenkov/roslyn,tmeschter/roslyn,sharwell/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,heejaechang/roslyn,jmarolf/roslyn,brettfo/roslyn,mgoertz-msft/roslyn,abock/roslyn,Hosch250/roslyn,bkoelman/roslyn,xasx/roslyn,mattscheffer/roslyn,CyrusNajmabadi/roslyn,shyamnamboodiripad/roslyn,KevinRansom/roslyn,bkoelman/roslyn,tannergooding/roslyn,jasonmalinowski/roslyn,VSadov/roslyn,dotnet/roslyn,DustinCampbell/roslyn,bartdesmet/roslyn,panopticoncentral/roslyn,MichalStrehovsky/roslyn,shyamnamboodiripad/roslyn,weltkante/roslyn,jmarolf/roslyn,OmarTawfik/roslyn,bartdesmet/roslyn,bartdesmet/roslyn,swaroop-sridhar/roslyn,Hosch250/roslyn,ErikSchierboom/roslyn,Hosch250/roslyn,AmadeusW/roslyn,tmeschter/roslyn,eriawan/roslyn