[docs] Add PlantUML to the deploy_docs GitHub action to generate diagrams

Author: thoni56

.github/workflows/deploy_docs.yaml

@@ -19,10 +19,10 @@ jobs:
         with:
           python-version: '3.x'  # Ensures Python 3.x is installed, adjust as needed for your project
 
-      - name: Install Graphviz
+      - name: Install Graphviz and PlantUML
         run: |
-          sudo apt-get update && sudo apt-get install -y graphviz
-        
+          sudo apt-get update && sudo apt-get install -y graphviz plantuml
+
       - name: Install Asciidoctor and Asciidoctor-Diagram
         run: |
           gem install asciidoctor asciidoctor-diagram asciidoctor-pdf --user-install