Update NGCHMSupportFiles action to include knitr

Updating this action to install knitr before checking the
NGCHMSupportFiles R package so that the vignette can build.

Addresses issue #534

.github/workflows/NGCHMSupportFiles_release.yml

@@ -69,6 +69,13 @@ jobs:
           sed -i.bak '/Version:/d' DESCRIPTION
           echo "Version: ${{ steps.get_version_number.outputs.version_number }}" >> DESCRIPTION
           cat DESCRIPTION
+      - name: Set up R enviornment
+        uses: r-lib/actions/setup-r@v2
+      - name: Install knitr (for vignette)
+        uses: r-lib/actions/setup-r-dependencies@v2
+        with:
+          packages: knitr
+          working-directory: NGCHMSupportFiles
       - name: Verify NGCHMSupportFile R build
         run: |
           cd NGCHMSupportFiles