Fix homepage readme (#468)

* Rename .github/README.md to .github/WORKFLOW.md

* Add link to WORKFLOW.md in Testing Guide

* Update Testing Guide reference to WORKFLOW.md

Author: aabrown100-git

.github/README.md .github/WORKFLOW.md.github/README.md renamed to .github/WORKFLOW.md

@@ -7,6 +7,8 @@ Running a test case requires
 - Install Git LFS used to download test data
 - Build svZeroDSolver (only required from certain tests)
 
+All the integration testing steps described below are automatically performed upon pull requests to the main branch, using GitHub Actions. See [WORKFLOW.md](../.github/WORKFLOW.md) for more details.
+
 # Build svMultiPhysics
 svMultiPhysics can be built following these [instructions](../README.md).