Add documentation for mermaid init config override (#317)

* Add documentation for mermaid init config override
* Capitalize Mermaid

Co-authored-by: Collin Brooks <cbrooks@sentryds.com>

exampleSite/content/docs/shortcodes/mermaid.md

@@ -2,6 +2,13 @@
 
 [Mermaid](https://mermaidjs.github.io/) is library for generating svg charts and diagrams from text.
 
+{{< hint info >}}
+**Override Mermaid Initialization Config**
+
+To override the [initialization config](https://mermaid-js.github.io/mermaid/#/Setup) for Mermaid,
+create a `mermaid.json` file in your `assets` folder!
+{{< /hint >}}
+
 ## Example
 
 {{< columns >}}
@@ -36,3 +43,4 @@ sequenceDiagram
 {{< /mermaid >}}
 
 {{< /columns >}}
+