Connection pool docs

[zuozp8]

Description

It would be great to explain (for example in client-configuration.md that single connection is sufficient most of the time and therefore there is no need for connection pooling.

I was looking in docs for options regarding connection pools (as I usually do when I set up the database client) and i found none (except for isolated connection pool). As I looked briefly it seems that commands are sent to the server as fast as the underlying socket allows it

[rickyssj2]

I have updated the docs. Let me know if anything else is needed. Thanks :)