Update CONTRIBUTING.md

Co-authored-by: Dave Bort <[email protected]>

Author: mergennachin

CONTRIBUTING.md

@@ -215,7 +215,7 @@ must work with threading**
 
 ## Testing
 
-### Running Tests
+### Running Tests Locally
 
 The `sh test/build_size_test.sh` script will compile the runtime along with portable kernels.
 The `test/run_oss_cpp_tests.sh` script will build and run C++ tests locally.