hub(prometheus): Add callout to StatsD (#1384)
hub(prometheus): Add callout to StatsD (#1384)

* hub(prometheus): Add callout to StatsD

Adds callout warning users with high throughputs to refer to the StatsD plugin

* Update index.md

Mashape/getkong.org,Mashape/getkong.org,Mashape/getkong.org