Tweak README for GitHub Actions build (#213)

Signed-off-by: Thomas Powell <[email protected]>

README.md

@@ -4,8 +4,15 @@ A .NET Assembly to facilitate communication between Chef and PowerShell on the W
 
 ### Development Prerequisites
 
-Binaries can be built with Habitat. See the PowerShell script .\.expeditor\build_gems.ps1 to test your changes
-Then run .\.expeditor\manual_gem_release.ps1 to build the gem and push it out. Releng does not have a Windows centric
+Binaries can be built with Habitat. See the PowerShell script `.\.expeditor\build_gems.ps1` to test your changes locally.
+
+### Build on merge
+
+`workflows/gem-build.yml` should normally build on merge to `main`
+
+### Manual build
+
+Then run `.\.expeditor\manual_gem_release.ps1` to build the gem and push it out. Releng does not have a Windows centric
 facility to build and push gems to Artifactory automatically. You will need:
 1) Access to the Chef internal Artifactory repo
 2) a Windows build system