Document rate limits for pageview API end points (#622)
Document rate limits for pageview API end points (#622)

Add a bullet point clearly documenting the per-entrypoint limits before
enforcing them.
gwicke/restbase,wikimedia/restbase,Pchelolo/restbase,inverno/restbase,wikimedia/mediawiki-services-restbase,cscott/restbase,milimetric/restbase,gwicke/restbase,inverno/restbase,eevans/restbase,d00rman/restbase,milimetric/restbase,cscott/restbase,wikimedia/restbase,d00rman/restbase,wikimedia/mediawiki-services-restbase,eevans/restbase,Pchelolo/restbase