feat: mermaid shortcode support code block inside

content/markdown-syntax.md

@@ -134,6 +134,18 @@ Most <mark>salamanders</mark> are nocturnal, and hunt for insects, worms, and ot
 ## Mermaid
 
 {% mermaid() %}
+
+graph TD;
+A-->B;
+A-->C;
+B-->D;
+C-->D;
+
+{% end %}
+
+{% mermaid() %}
+
+```
 sequenceDiagram
     participant Alice
     participant Bob
@@ -145,6 +157,25 @@ Note right of John: Rational thoughts <br/>prevail!
     John-->>Alice: Great!
     John->>Bob: How about you?
     Bob-->>John: Jolly good!
+```
+
+{% end %}
+
+{% mermaid() %}
+
+```mermaid
+gitGraph
+       commit
+       commit
+       branch develop
+       commit
+       commit
+       commit
+       checkout main
+       commit
+       commit
+```
+
 {% end %}
 
 ## Admonition

templates/shortcodes/mermaid.html

@@ -1,3 +1,3 @@
 <pre class="mermaid bg-white">
-  {{ body }}
+  {{ body | trim_start_matches(pat="```mermaid") | trim_start_matches(pat="```") | trim_end_matches(pat="```") }}
 </pre>