Write blog post about sql-press

[elbart]

[jayvdb]

The repo description says it is built "on top of refinery", which I guess means https://github.com/rust-db/refinery
However that doesnt appear as a dependency.

btw, https://github.com/fabianlindfors/reshape and https://git.irde.st/spacekookie/barrel are probably worth investigating for comparisons in the blog post, or new features for sql-press.