Ghost Blog and Mermaid
I'm fond of Mermaid.js, a library for creating diagrams from code-like input. It can be easily integrated into markdown based renderers like VSCode, and into HTML renderers like this web page.
graph LR
A --> B --> C --> A
B --> D
The diagram above was created with this snippet in a Ghost-HTML block:
<div class="mermaid">
graph LR
A --> B --> C --> A
B --> D
</div>
I added the following to the Footer Code Injection option in the Ghost admin interface to make it work:
<script src="https://unpkg.com/mermaid@8.8.4/dist/mermaid.min.js"></script>
<script>mermaid.initialize({startOnLoad:true});</script>