Update README.md

README.md

@@ -1 +1,26 @@
-# testrepo
+# testrepo
+
+![rendered image description](relative/path/to/rendered_image. svg or png )
+<details>
+  <summary>diagram source</summary>
+  This details block is collapsed by default when viewed in GitHub. This hides the mermaid graph definition, while the rendered image
+  linked above is shown. The details tag has to follow the image tag. (newlines allowed)
+
+```mermaid
+graph LR
+    A[README.md]
+    B{Find mermaid graphs<br>and image paths}
+    C[[docker mermaid-cli]]
+    D[[docker mermaid-cli]]
+    E(Graph 1 png image)
+    F(Graph 2 svg image)
+
+    A -->|passed to| B
+    subgraph render-md-mermaid.sh
+      B --> |path/to/image1.png<br>+mermaid source| C
+      B --> |path/to/image2.svg<br>+mermaid source| D
+    end
+    C --> E
+    D --> F
+```
+</details>