Rewrote some sentences for readability.

There was an odd sentence in this doc, I updated it to reflect what is written in the Chinese version.

* go sql insert example

* fix go doc bug

* adjust cluster part; change mysql to sql

* add go connect example using af

* go stmt example

* go influxdb line example

* go telnet line insert example

* reduce sample data

* go json insert example

* go query example