Tweak workflows (ProjectPythia#513)

* Tweak workflows

* Fix whitespace

Author: brian-rose

.github/workflows/nightly-build.yaml

@@ -9,6 +9,8 @@ jobs:
   build:
     if: ${{ github.repository_owner == 'ProjectPythia' }}
     uses: ProjectPythia/cookbook-actions/.github/workflows/build-book.yaml@main
+    with:
+      base_url: ''
 
   deploy:
     needs: build

.github/workflows/publish-site.yaml

@@ -16,5 +16,3 @@ jobs:
   deploy:
     needs: build
     uses: ProjectPythia/cookbook-actions/.github/workflows/deploy-book.yaml@main
-    with:
-      publish_dir: 'portal/_build/html'