Cleanup/wg init (#260)

* remove wg_init and wg_finalize from functional tests

* Remove wg_init and wg_finalize from examples

* deprecate wg_init/finalize

* Updated docs

* Typo in documentation

---------

Co-authored-by: Yiltan <yiltan@amd.com>

[ROCm/rocshmem commit: 6e7277b544]

projects/rocshmem/tests/functional_tests/empty_tester.cpp

@@ -35,11 +35,9 @@ __global__ void EmptyTest(int loop, int skip, long long int *start_time,
                           long long int *end_time, int size, TestType type,
                           ShmemContextType ctx_type) {
   __shared__ rocshmem_ctx_t ctx;
-  rocshmem_wg_init();
   rocshmem_wg_ctx_create(ctx_type, &ctx);
 
   rocshmem_wg_ctx_destroy(&ctx);
-  rocshmem_wg_finalize();
 }
 
 /******************************************************************************