Update WindowsBuild.md
Update WindowsBuild.md

Add documentation about enabling developer mode and ensure that the toolchain is built in release mode as debug is extremely slow.
aschwaighofer/swift,roambotics/swift,gregomni/swift,tkremenek/swift,parkera/swift,harlanhaskins/swift,benlangmuir/swift,allevato/swift,airspeedswift/swift,CodaFi/swift,atrick/swift,apple/swift,jmgc/swift,jckarter/swift,jckarter/swift,rudkx/swift,tkremenek/swift,gregomni/swift,benlangmuir/swift,stephentyrone/swift,apple/swift,nathawes/swift,atrick/swift,tkremenek/swift,xwu/swift,xwu/swift,JGiola/swift,aschwaighofer/swift,jmgc/swift,stephentyrone/swift,jmgc/swift,roambotics/swift,hooman/swift,xwu/swift,ahoppen/swift,airspeedswift/swift,allevato/swift,hooman/swift,gregomni/swift,parkera/swift,apple/swift,jmgc/swift,parkera/swift,nathawes/swift,jmgc/swift,roambotics/swift,jckarter/swift,hooman/swift,harlanhaskins/swift,allevato/swift,jmgc/swift,aschwaighofer/swift,ahoppen/swift,CodaFi/swift,ahoppen/swift,glessard/swift,tkremenek/swift,harlanhaskins/swift,JGiola/swift,jmgc/swift,jckarter/swift,parkera/swift,parkera/swift,nathawes/swift,allevato/swift,airspeedswift/swift,jckarter/swift,xwu/swift,stephentyrone/swift,rudkx/swift,allevato/swift,apple/swift,roambotics/swift,roambotics/swift,jckarter/swift,atrick/swift,glessard/swift,apple/swift,rudkx/swift,aschwaighofer/swift,tkremenek/swift,glessard/swift,JGiola/swift,stephentyrone/swift,atrick/swift,benlangmuir/swift,JGiola/swift,parkera/swift,nathawes/swift,apple/swift,harlanhaskins/swift,JGiola/swift,aschwaighofer/swift,harlanhaskins/swift,airspeedswift/swift,hooman/swift,rudkx/swift,hooman/swift,airspeedswift/swift,aschwaighofer/swift,nathawes/swift,jckarter/swift,CodaFi/swift,CodaFi/swift,xwu/swift,glessard/swift,tkremenek/swift,allevato/swift,airspeedswift/swift,hooman/swift,hooman/swift,harlanhaskins/swift,xwu/swift,rudkx/swift,xwu/swift,parkera/swift,airspeedswift/swift,ahoppen/swift,gregomni/swift,glessard/swift,roambotics/swift,rudkx/swift,CodaFi/swift,aschwaighofer/swift,CodaFi/swift,gregomni/swift,glessard/swift,atrick/swift,stephentyrone/swift,tkremenek/swift,stephentyrone/swift,benlangmuir/swift,ahoppen/swift,benlangmuir/swift,atrick/swift,benlangmuir/swift,JGiola/swift,stephentyrone/swift,nathawes/swift,gregomni/swift,parkera/swift,ahoppen/swift,allevato/swift,nathawes/swift,harlanhaskins/swift,CodaFi/swift