Update and improve storage docs.
Update and improve storage docs.

ddfreyne/prometheus-docs,dln/docs,prometheus/docs,tcolgate/docs,ChaoticMind/docs,pdbogen/docs,open-falcon/open-falcon.github.io,vic3lord/docs,tcolgate/docs,vic3lord/docs,prometheus/docs,vic3lord/docs,dln/docs,open-falcon/open-falcon.github.io,pdbogen/docs,du2016/prometheus-docs,jimmidyson/docs,jimmidyson/docs,dato/prometheus-docs,prometheus/docs,dato/prometheus-docs,chosenken/docs,du2016/prometheus-docs,ddfreyne/prometheus-docs,evanphx/docs,open-falcon/open-falcon.github.io,jmptrader/docs,pdbogen/docs,jmptrader/docs,Cepave/openfalcon.io,du2016/prometheus-docs,tcolgate/docs,evanphx/docs,ddfreyne/prometheus-docs,chosenken/docs,chosenken/docs,ChaoticMind/docs,Cepave/openfalcon.io,Cepave/openfalcon.io,ddfreyne/prometheus-docs,dln/docs,dato/prometheus-docs,chosenken/docs,jmptrader/docs,ChaoticMind/docs,evanphx/docs,jimmidyson/docs