Doc: Add a doc page about different timeouts in Go clients and it's impacts

[kavirajk]

Recently I have lots questions about stale connections and connection timeouts. Things get interesting if it involves proxies in between.

Things I need to cover

1. Connection timeouts
2. Read/Write timeouts
3. Stale connections
4. Impact of different headers (in HTTP) like Keep-Alive
5. Proxies
6. Retries

[kavirajk]

from @mshustov : One of the issue is people try to use TCP timeouts (based on our docs). And complain why it doesn't work with HTTP in same way.