Add documentation describing ROCPROFSYS_USE_RCCP (#110)

* Add documentation describing ROCPROFSYS_USE_RCCP

Signed-off-by: David Galiffi <David.Galiffi@amd.com>

* Update wordlist

Signed-off-by: David Galiffi <David.Galiffi@amd.com>

* Update CHANGELOGS.md

---------

Signed-off-by: David Galiffi <David.Galiffi@amd.com>
Co-authored-by: David Galiffi <David.Galiffi@amd.com>

projects/rocprofiler-systems/docs/how-to/configuring-runtime-options.rst

@@ -225,6 +225,22 @@ and memory copy operations submitted. With the
 ``ROCPROFSYS_ROCM_GROUP_BY_QUEUE=ON`` setting, the trace will display HSA queues
 to which these kernel and memory operations were submitted.
 
+ROCPROFSYS_USE_RCCLP
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Use the setting ``ROCPROFSYS_USE_RCCLP = ON`` to enable profiling and tracing of
+ROCm Communication Collectives Library (RCCL, also pronounced as 'Rickle'). When this setting is enabled,
+ROCm Systems Profiler will trace the RCCL API calls and collect performance metrics related to collective operations.
+
+The image below shows an example of a Perfetto trace with RCCL communication data and API tracing enabled:
+
+.. image:: ../data/rccl-comm-recv.png
+   :alt: Perfetto tracks with RCCL Communication Data and API tracing
+
+.. note::
+   There is a known issue which causes the application to exit with an error. However, the trace data can still be found in the output directory.
+   This issue is being tracked internally.
+
 Exploring GPU Metrics
 ---------------------