Install mkdocs macro plugin for pages CI (#136)

Author: peterohanley-galois

.github/workflows/deploy-to-web.yml

@@ -28,7 +28,7 @@ jobs:
           python-version: 3.x
 
       - name: Install Material for MkDocs
-        run: pip install mkdocs-material
+        run: pip install mkdocs-material mkdocs-macros-plugin
 
       - name: Clean the build directory 
         run: make clean