Review and update whitespaces in mermaid and KaTeX to improve shortcode nesting

layouts/_markup/render-codeblock-mermaid.html

@@ -1,12 +1,10 @@
-{{ if not (.Page.Store.Get "mermaid") }}
-<!-- Include mermaid only first time -->
-<script src="{{ "mermaid.min.js" | relURL }}"></script>
-{{ with resources.Get "mermaid.json" }}
-  <script>mermaid.initialize({{ .Content | safeJS }})</script>
-{{ end }}
-{{ .Page.Store.Set "mermaid" true }}
-{{ end }}
-
-<pre class="mermaid">
-  {{- .Inner -}}
-</pre>
+{{- /* remove whitespaces */ -}}
+<pre class="mermaid">{{ .Inner | htmlEscape | safeHTML -}}</pre>
+{{- if not (.Page.Store.Get "mermaid") -}}
+  {{- /* Include mermaid only first time */ -}}
+  <script src="{{ "mermaid.min.js" | relURL }}"></script>
+  {{- with resources.Get "mermaid.json" | minify -}}
+    <script>mermaid.initialize({{ .Content | safeJS }})</script>
+  {{- end -}}
+  {{- .Page.Store.Set "mermaid" true -}}
+{{- end -}}