taking a stab at porting over the FAQ from wikidot

Left most of it the same, but changed a few relevant details.
P.S. 160k metrics/minute "ain't shit" anymore. I can benchmark 100k metrics/sec on a single i2.4xlarge (non-persistent SSDs), but I'd rather get a number from someone like Booking.com in there, who uses it in a **very large** production architecture.