[Stdlib] Update the SeeAlso docs for flatten()
[Stdlib] Update the SeeAlso docs for flatten()

flatten() was still referencing `joinWithSeparator(_:)` even though
that's now been renamed to `joined(separator:)`.

allevato/swift,codestergit/swift,milseman/swift,tardieu/swift,JGiola/swift,apple/swift,arvedviehweger/swift,natecook1000/swift,atrick/swift,austinzheng/swift,xedin/swift,roambotics/swift,kperryua/swift,milseman/swift,jmgc/swift,karwa/swift,modocache/swift,atrick/swift,gottesmm/swift,modocache/swift,shajrawi/swift,amraboelela/swift,tjw/swift,natecook1000/swift,harlanhaskins/swift,kstaring/swift,lorentey/swift,danielmartin/swift,CodaFi/swift,tinysun212/swift-windows,OscarSwanros/swift,hooman/swift,swiftix/swift,xedin/swift,lorentey/swift,CodaFi/swift,therealbnut/swift,uasys/swift,russbishop/swift,danielmartin/swift,harlanhaskins/swift,airspeedswift/swift,roambotics/swift,hughbe/swift,gmilos/swift,brentdax/swift,jopamer/swift,nathawes/swift,roambotics/swift,therealbnut/swift,OscarSwanros/swift,tardieu/swift,tjw/swift,calebd/swift,calebd/swift,allevato/swift,tinysun212/swift-windows,therealbnut/swift,JaSpa/swift,gottesmm/swift,arvedviehweger/swift,hughbe/swift,harlanhaskins/swift,jopamer/swift,JaSpa/swift,parkera/swift,alblue/swift,sschiau/swift,frootloops/swift,xedin/swift,stephentyrone/swift,gregomni/swift,kstaring/swift,kstaring/swift,tardieu/swift,ben-ng/swift,jmgc/swift,djwbrown/swift,gmilos/swift,frootloops/swift,frootloops/swift,gribozavr/swift,codestergit/swift,benlangmuir/swift,arvedviehweger/swift,zisko/swift,lorentey/swift,jopamer/swift,kperryua/swift,codestergit/swift,therealbnut/swift,huonw/swift,swiftix/swift,apple/swift,arvedviehweger/swift,IngmarStein/swift,dreamsxin/swift,practicalswift/swift,hughbe/swift,huonw/swift,IngmarStein/swift,practicalswift/swift,uasys/swift,sschiau/swift,sschiau/swift,bitjammer/swift,OscarSwanros/swift,lorentey/swift,modocache/swift,zisko/swift,OscarSwanros/swift,airspeedswift/swift,shahmishal/swift,alblue/swift,codestergit/swift,ben-ng/swift,tinysun212/swift-windows,swiftix/swift,shajrawi/swift,kperryua/swift,deyton/swift,gregomni/swift,swiftix/swift,alblue/swift,practicalswift/swift,OscarSwanros/swift,jopamer/swift,tardieu/swift,return/swift,austinzheng/swift,hooman/swift,CodaFi/swift,kperryua/swift,hughbe/swift,natecook1000/swift,alblue/swift,manavgabhawala/swift,CodaFi/swift,ken0nek/swift,huonw/swift,rudkx/swift,danielmartin/swift,parkera/swift,parkera/swift,jopamer/swift,practicalswift/swift,shajrawi/swift,huonw/swift,tkremenek/swift,tinysun212/swift-windows,shahmishal/swift,jmgc/swift,airspeedswift/swift,xedin/swift,lorentey/swift,OscarSwanros/swift,kperryua/swift,alblue/swift,shajrawi/swift,return/swift,deyton/swift,gmilos/swift,shahmishal/swift,airspeedswift/swift,amraboelela/swift,practicalswift/swift,aschwaighofer/swift,allevato/swift,felix91gr/swift,gottesmm/swift,alblue/swift,karwa/swift,nathawes/swift,brentdax/swift,uasys/swift,frootloops/swift,tjw/swift,karwa/swift,austinzheng/swift,milseman/swift,parkera/swift,JGiola/swift,sschiau/swift,hooman/swift,devincoughlin/swift,gregomni/swift,return/swift,jtbandes/swift,swiftix/swift,austinzheng/swift,arvedviehweger/swift,kstaring/swift,shajrawi/swift,karwa/swift,hooman/swift,modocache/swift,natecook1000/swift,uasys/swift,rudkx/swift,glessard/swift,manavgabhawala/swift,benlangmuir/swift,aschwaighofer/swift,manavgabhawala/swift,sschiau/swift,shajrawi/swift,parkera/swift,jtbandes/swift,atrick/swift,bitjammer/swift,devincoughlin/swift,calebd/swift,hughbe/swift,parkera/swift,glessard/swift,rudkx/swift,milseman/swift,airspeedswift/swift,xwu/swift,ben-ng/swift,JaSpa/swift,aschwaighofer/swift,stephentyrone/swift,djwbrown/swift,ben-ng/swift,bitjammer/swift,parkera/swift,bitjammer/swift,gribozavr/swift,Jnosh/swift,JGiola/swift,IngmarStein/swift,jmgc/swift,ken0nek/swift,brentdax/swift,devincoughlin/swift,zisko/swift,bitjammer/swift,danielmartin/swift,devincoughlin/swift,JaSpa/swift,deyton/swift,milseman/swift,calebd/swift,allevato/swift,practicalswift/swift,gregomni/swift,JaSpa/swift,natecook1000/swift,aschwaighofer/swift,modocache/swift,harlanhaskins/swift,jtbandes/swift,return/swift,tjw/swift,gribozavr/swift,xedin/swift,uasys/swift,bitjammer/swift,calebd/swift,ken0nek/swift,stephentyrone/swift,natecook1000/swift,practicalswift/swift,sschiau/swift,jtbandes/swift,Jnosh/swift,jmgc/swift,karwa/swift,allevato/swift,brentdax/swift,uasys/swift,gregomni/swift,harlanhaskins/swift,benlangmuir/swift,jtbandes/swift,russbishop/swift,sschiau/swift,gribozavr/swift,manavgabhawala/swift,shahmishal/swift,shahmishal/swift,xwu/swift,glessard/swift,felix91gr/swift,russbishop/swift,russbishop/swift,kperryua/swift,airspeedswift/swift,manavgabhawala/swift,ben-ng/swift,Jnosh/swift,tinysun212/swift-windows,swiftix/swift,tkremenek/swift,tkremenek/swift,tardieu/swift,djwbrown/swift,karwa/swift,kstaring/swift,amraboelela/swift,austinzheng/swift,felix91gr/swift,djwbrown/swift,austinzheng/swift,russbishop/swift,tkremenek/swift,calebd/swift,IngmarStein/swift,gribozavr/swift,dreamsxin/swift,xedin/swift,gribozavr/swift,glessard/swift,shahmishal/swift,felix91gr/swift,therealbnut/swift,codestergit/swift,stephentyrone/swift,ken0nek/swift,ahoppen/swift,aschwaighofer/swift,atrick/swift,gottesmm/swift,kperryua/swift,return/swift,sschiau/swift,jckarter/swift,atrick/swift,JaSpa/swift,russbishop/swift,apple/swift,felix91gr/swift,tjw/swift,devincoughlin/swift,xwu/swift,jckarter/swift,tjw/swift,deyton/swift,allevato/swift,apple/swift,roambotics/swift,Jnosh/swift,harlanhaskins/swift,xwu/swift,tinysun212/swift-windows,lorentey/swift,brentdax/swift,benlangmuir/swift,zisko/swift,roambotics/swift,jmgc/swift,aschwaighofer/swift,airspeedswift/swift,Jnosh/swift,nathawes/swift,huonw/swift,devincoughlin/swift,ben-ng/swift,djwbrown/swift,amraboelela/swift,kstaring/swift,allevato/swift,nathawes/swift,milseman/swift,zisko/swift,jtbandes/swift,ben-ng/swift,ahoppen/swift,frootloops/swift,frootloops/swift,harlanhaskins/swift,hughbe/swift,tkremenek/swift,djwbrown/swift,devincoughlin/swift,manavgabhawala/swift,amraboelela/swift,aschwaighofer/swift,shahmishal/swift,jckarter/swift,ken0nek/swift,xwu/swift,danielmartin/swift,felix91gr/swift,tjw/swift,hooman/swift,rudkx/swift,ahoppen/swift,calebd/swift,tardieu/swift,alblue/swift,ken0nek/swift,deyton/swift,deyton/swift,devincoughlin/swift,therealbnut/swift,benlangmuir/swift,kstaring/swift,deyton/swift,karwa/swift,glessard/swift,return/swift,ahoppen/swift,arvedviehweger/swift,jopamer/swift,roambotics/swift,amraboelela/swift,amraboelela/swift,CodaFi/swift,ahoppen/swift,hooman/swift,lorentey/swift,tardieu/swift,gribozavr/swift,benlangmuir/swift,jckarter/swift,xedin/swift,shajrawi/swift,gmilos/swift,gmilos/swift,shahmishal/swift,jtbandes/swift,rudkx/swift,gmilos/swift,gottesmm/swift,codestergit/swift,danielmartin/swift,hooman/swift,bitjammer/swift,zisko/swift,tkremenek/swift,manavgabhawala/swift,stephentyrone/swift,gottesmm/swift,return/swift,JaSpa/swift,stephentyrone/swift,parkera/swift,therealbnut/swift,swiftix/swift,karwa/swift,Jnosh/swift,lorentey/swift,danielmartin/swift,gribozavr/swift,gmilos/swift,stephentyrone/swift,russbishop/swift,jckarter/swift,nathawes/swift,modocache/swift,nathawes/swift,brentdax/swift,jopamer/swift,jmgc/swift,felix91gr/swift,jckarter/swift,tinysun212/swift-windows,nathawes/swift,milseman/swift,codestergit/swift,atrick/swift,CodaFi/swift,gregomni/swift,jckarter/swift,huonw/swift,natecook1000/swift,JGiola/swift,ahoppen/swift,hughbe/swift,CodaFi/swift,austinzheng/swift,glessard/swift,frootloops/swift,tkremenek/swift,Jnosh/swift,practicalswift/swift,gottesmm/swift,IngmarStein/swift,uasys/swift,IngmarStein/swift,arvedviehweger/swift,modocache/swift,huonw/swift,rudkx/swift,OscarSwanros/swift,djwbrown/swift,JGiola/swift,xedin/swift,shajrawi/swift,zisko/swift,IngmarStein/swift,JGiola/swift,apple/swift,ken0nek/swift,xwu/swift,xwu/swift,apple/swift,brentdax/swift