docs updated

Author: behnamasadi

docs/doxygen.md

@@ -8,14 +8,15 @@ The most important sections are:
 
 **PROJECT_NAME**
 
-```PROJECT_NAME= "Simple Example"
+```
+PROJECT_NAME= "Simple Example"
 ```
 
 
 **INPUT**
 path to your source code:
 ```
-INPUT=./source
+INPUT=/cpp_tutorials/src
 ```
 
 **DOT_PATH**
@@ -33,8 +34,7 @@ DOT_PATH =/usr/bin/dot
 **OUTPUT**
 
 ```
-HTML_OUTPUT            = doc/html
-OUTPUT_DIRECTORY       = .
+HTML_OUTPUT            = /cpp_tutorials/html
 ```
 
 or you can run 
@@ -55,6 +55,38 @@ and see your modified values in red:
 <img src="images/doxygen5.png"  width="80%"  height="80%"/>
 
 
+
+    
+    
+
+
 ## Doxygen UML Diagram and Graph Legend
 
 [Doxygen uml diagram and graph legend](https://www.doxygen.nl/manual/examples/diagrams/html/graph_legend.html)
+
+
+## Update Dockerfile
+
+```
+RUN apt-get update && apt-get install -y \
+    git \	
+    cmake \
+    ninja-build \
+    doxygen \
+    build-essential \
+    graphviz \
+    && rm -rf /var/lib/apt/lists/*
+```
+[Full example](../Dockerfile)  
+
+## Update GitHub Action 
+
+```
+      - name: Generate Doxygen documentation
+        run: docker run --rm -v ${{ github.workspace }}:/cpp_tutorials mycpp_image:latest doxygen /cpp_tutorials/Doxyfile
+
+      - name: List generated documentation files
+        run: docker run --rm -v ${{ github.workspace }}:/cpp_tutorials mycpp_image:latest ls -la /cpp_tutorials/docs
+```
+
+[Full example](../.github/workflows/docker-build.yml)