RethinkDB State Store Metadata

[cicoyle]

The rethinkdb state store metadata here in the docs needs to be updated to match these supported metadata fields.

Specifically the following are missing:

1. addresses
2. enableTLS
3. clientCert
4. clientKey
5. timeout
6. useJSONNumber
7. numRetries
8. hostDecayDuration
9. useOpentracing
10. writeTimeout
11. readTimeout
12. handshakeVersion
13. keepAlivePeriod
14. maxIdle
15. authKey
16. initialCap
17. maxOpen
18. discoverHosts
19. nodeRefreshInterval

[cicoyle]

shoutout to @sicoyle for finding this missing information!