Add section Preparing kernel arguments (#541)

* Add section Preparing kernel arguments

* Some review suggestions

* Provide NumPy type table

* Spelling

* Kernel arg is either host or device

* Simplify testStruct

* Extend with int8_t

* Extend with int16_t

* Extend with int32_t

* Extend with uint64_t

* Align true for code sample

* Align true for documentation

* Use intp instead of uint64 for addresses

* apply nits

* Apply suggestions from code review

* Reviews

Author: vzhurba01