DOC-4080 Sorted Set (ZADD and ZRANGE commands) examples (#3944)

* DOC-4080 added ZADD example

* DOC-4080 rename file and add ZRANGE examples

* DOC-4080 delete sorted set obj after tests

* DOC-4080 rename with  suffix

* DOC-4080 un-hide useful imports

Author: andy-stark-redis