Enable Mermaid diagram rendering via superfences custom_fences

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jayhesselberth

zensical.toml

@@ -59,6 +59,9 @@ toggle.name = "Switch to light mode"
 [project.markdown_extensions.pymdownx.details]
 
 [project.markdown_extensions.pymdownx.superfences]
+custom_fences = [
+  { name = "mermaid", class = "mermaid", format = "pymdownx.superfences.fence_code_format" }
+]
 
 [project.markdown_extensions.pymdownx.tabbed]
 alternate_style = true