Add page about refactoring exercises
Add page about refactoring exercises

NobbZ/docs,rchavarria/docs,spazm/docs,arashbi/docs,canweriotnow/docs,k4rtik/docs,alexclarkofficial/docs,lfex/exercism-docs,NobbZ/docs,ZacharyRSmith/docs,exercism/DEPRECATED.help.exercism.io,arashbi/docs,lfex/exercism-docs,spazm/docs,rchavarria/docs,alexclarkofficial/docs,ekse/exercism-docs,exercism/DEPRECATED.help.exercism.io,yurrriq/docs,ZacharyRSmith/docs,ekse/exercism-docs,k4rtik/docs,canweriotnow/docs,yurrriq/docs