[docs] CToSwift: Tweak wording around "overrides"
[docs] CToSwift: Tweak wording around "overrides"

The previous wording referred to a method or property satisfying a
protocol requirement as an "override", which both Clang and the Swift
Clang Importer use internally sometimes. But most people who program
Objective-C (or Swift) don't think of this as an override, so this
document shouldn't use that language. (Thanks, Varun!)

jmgc/swift,gribozavr/swift,stephentyrone/swift,jckarter/swift,lorentey/swift,atrick/swift,CodaFi/swift,allevato/swift,xwu/swift,harlanhaskins/swift,gregomni/swift,stephentyrone/swift,gregomni/swift,lorentey/swift,allevato/swift,allevato/swift,harlanhaskins/swift,parkera/swift,karwa/swift,jckarter/swift,CodaFi/swift,karwa/swift,airspeedswift/swift,CodaFi/swift,allevato/swift,CodaFi/swift,nathawes/swift,parkera/swift,gribozavr/swift,apple/swift,rudkx/swift,tkremenek/swift,JGiola/swift,glessard/swift,benlangmuir/swift,glessard/swift,rudkx/swift,jmgc/swift,aschwaighofer/swift,aschwaighofer/swift,jckarter/swift,lorentey/swift,xwu/swift,xwu/swift,glessard/swift,roambotics/swift,atrick/swift,aschwaighofer/swift,JGiola/swift,nathawes/swift,jmgc/swift,allevato/swift,gribozavr/swift,benlangmuir/swift,tkremenek/swift,jmgc/swift,harlanhaskins/swift,xwu/swift,airspeedswift/swift,ahoppen/swift,apple/swift,hooman/swift,karwa/swift,airspeedswift/swift,glessard/swift,roambotics/swift,jmgc/swift,tkremenek/swift,stephentyrone/swift,lorentey/swift,karwa/swift,ahoppen/swift,CodaFi/swift,atrick/swift,jckarter/swift,roambotics/swift,jckarter/swift,nathawes/swift,parkera/swift,ahoppen/swift,allevato/swift,apple/swift,stephentyrone/swift,nathawes/swift,karwa/swift,xwu/swift,roambotics/swift,ahoppen/swift,harlanhaskins/swift,tkremenek/swift,CodaFi/swift,airspeedswift/swift,hooman/swift,karwa/swift,JGiola/swift,harlanhaskins/swift,apple/swift,roambotics/swift,hooman/swift,benlangmuir/swift,parkera/swift,gribozavr/swift,lorentey/swift,atrick/swift,benlangmuir/swift,ahoppen/swift,stephentyrone/swift,tkremenek/swift,hooman/swift,ahoppen/swift,aschwaighofer/swift,gribozavr/swift,lorentey/swift,stephentyrone/swift,aschwaighofer/swift,jckarter/swift,lorentey/swift,stephentyrone/swift,airspeedswift/swift,parkera/swift,airspeedswift/swift,jckarter/swift,JGiola/swift,parkera/swift,hooman/swift,nathawes/swift,aschwaighofer/swift,gribozavr/swift,jmgc/swift,apple/swift,rudkx/swift,apple/swift,parkera/swift,atrick/swift,harlanhaskins/swift,lorentey/swift,benlangmuir/swift,gribozavr/swift,hooman/swift,glessard/swift,gregomni/swift,tkremenek/swift,glessard/swift,gregomni/swift,benlangmuir/swift,rudkx/swift,karwa/swift,atrick/swift,harlanhaskins/swift,nathawes/swift,roambotics/swift,parkera/swift,xwu/swift,gregomni/swift,gribozavr/swift,hooman/swift,jmgc/swift,aschwaighofer/swift,allevato/swift,rudkx/swift,JGiola/swift,karwa/swift,tkremenek/swift,airspeedswift/swift,JGiola/swift,nathawes/swift,xwu/swift,gregomni/swift,CodaFi/swift,rudkx/swift