"How-To" document describing network performance profiling (#145)

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Co-authored-by: David Galiffi <David.Galiffi@amd.com>
Co-authored-by: Peter Park <peter.park@amd.com>
Co-authored-by: Pratik Basyal <pratik.basyal@amd.com>

[ROCm/rocprofiler-systems commit: de84a277f2]

projects/rocprofiler-systems/docs/sphinx/_toc.yml.in

@@ -35,6 +35,8 @@ subtrees:
           title: Performing causal profiling
         - file: how-to/profiling-python-scripts.rst
           title: Profiling Python scripts
+        - file: how-to/nic-profiling.rst
+          title: Network performance profiling
     - file: how-to/understanding-rocprof-sys-output.rst
       title: Understanding the output
     - file: how-to/using-rocprof-sys-api.rst