Add tabbed content within document

* this minor change adds tabbed content within documents as shown at the
bottom of issue #821 in the documentation git
[here](rocky-linux/documentation#821)

Author: sspencerwire

mkdocs.yml

@@ -46,7 +46,8 @@ markdown_extensions:
   - pymdownx.highlight
   - pymdownx.superfences
   - pymdownx.keys
-  - pymdownx.tabbed
+  - pymdownx.tabbed:
+      alternate_style: true
   - pymdownx.details
   - pymdownx.tasklist
   - footnotes