Update SQL documentation & small typo fix api-877 (#1060)
Update SQL documentation & small typo fix api-877 (#1060)

* Change SQL documentation

* Add missing performance SQL section && refactore more info

* Review comments

* Remove extra whitespace

Co-authored-by: Metin Dumandag <e92964dda8cbab0174ce0496e48e6076d98b6959@gmail.com>

Co-authored-by: Metin Dumandag <e92964dda8cbab0174ce0496e48e6076d98b6959@gmail.com>
hazelcast-incubator/hazelcast-nodejs-client,hazelcast-incubator/hazelcast-nodejs-client