In .gitroot/plugins.yml of your root repository add:
1- url: https://gitroot.dev/releases/0.4.0/apex_markdown-0.0.4.wasm
2 checksum: sha256:7d4fe41a2c706cdef3353d6f2d09561952ee3ead9dd1ac0637803efc80ebe753
Apex_markdown convert markdown into html, use apex_code for code and apex_mermaid for mermaid charts.