mermaid shortcode mentioned in Note causes error

Couple of Notes in the [Diagram Guide](https://kubernetes.io/docs/contribute/style/diagram-guide/) include mention of the Hugo Mermaid shortcode. This generates a syntax error. Appears that Hugo interprets this as a Mermaid diagram.

```
{{< note >}}
You must include the `{{</*  mermaid */>}}`, `{{</* /mermaid */>}}` shortcode
tags at the start and end of the Mermaid code block. You should add a diagram
caption below the diagram. 
{{< /note >}}

```

This PR removes the `{{< mermaid >}}` mention inside the `{{< note >}} so that Hugo does not attempt to render a diagram.

Author: chrismetz09

content/en/docs/contribute/style/diagram-guide.md

@@ -242,7 +242,7 @@ Figure 17. A to B
 more text
 ```
 {{< note >}}
-You must include the `{{</*  mermaid */>}}`, `{{</* /mermaid */>}}` shortcode
+You must include the Hugo Mermaid shortcode
 tags at the start and end of the Mermaid code block. You should add a diagram
 caption below the diagram. 
 {{< /note >}}
@@ -429,7 +429,7 @@ Don't forget to check that your diagram renders correctly using the
 This section shows several examples of Mermaid diagrams. 
 
 {{< note >}}
-The code block examples omit the Hugo  `{{</*  mermaid */>}}`, `{{</* /mermaid */>}}`
+The code block examples omit the Hugo Mermaid
 shortcode tags. This allows you to copy the code block into the live editor
 to experiment on your own.
 Note that the live editor doesn't recognize Hugo shortcodes.