Update build instructions in devnotes.html
Update build instructions in devnotes.html

Making the instructions more specific, so the developer does not need to figure it out through trial and error.

This will resolve this issue: https://github.com/fsharp/FSharp.Compiler.Service/issues/845
dsyme/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service,Jand42/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,Jand42/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,Jand42/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service