[Grok-dev] macros tutorial

[Robert Marianski]

When working with macros with grok locally, I noticed that I was  
getting deprecation warnings when not using macros in the lookup. So  
"context/@@macrosview/macroname" was generating a deprecation warning,  
whereas "context/@@macrosview/macros/macroname" did not.

Just as an fyi, I updated the macros tutorial in several locations to  
use the "macros" spelling in the lookup.

Robert