Update docs.yml

replace . with _ in package name

Author: victordibia

.github/workflows/docs.yml

@@ -145,7 +145,7 @@ jobs:
       - name: pydoc-markdown install
         run: |
           python -m pip install --upgrade pip
-          pip install nr.util>=0.8.12
+          pip install nr_util>=0.8.12
           pip install pydoc-markdown pyyaml termcolor
           # Pin databind packages as version 4.5.0 is not compatible with pydoc-markdown.
           pip install databind.core==4.4.2 databind.json==4.4.2