Use Mermaid for Graph Generation

[sync-by-unito[bot]]

Hugo supports mermaid language with a builtin shortcode. The output of the Hugo Generator should create various illustrations using this capability. The graphs that come to mind:

• Plant/Pipe/Process data flow diagrams
• Saga as a sequence diagram
• Context maps for domains and contexts
• ERDs for Entities where connections relate to messages not key/foreign key connections.

┆Issue is synchronized with this Jira Story by Unito