Add new docsref page, fix docs border-radius issues (#38491)

* Add new docsref page, fix docs border-radius issues

* Remove commented out code

* Update docsref.md

* Fix no-code example, fix mobile styles

* Updates from review

* Fix block margin, remove margin-right from pre on mobile since no clipboard icons, adjust masthead snippet

* Fix errant styles for border-radius on homepage

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Co-authored-by: XhmikosR <xhmikosr@gmail.com>

site/layouts/shortcodes/example.html

@@ -21,7 +21,7 @@
 
 <div class="bd-example-snippet bd-code-snippet">
   {{- if eq $show_preview true -}}
-  <div{{ with $id }} id="{{ . }}"{{ end }} class="bd-example{{ with $class }} {{ . }}{{ end }}">
+  <div{{ with $id }} id="{{ . }}"{{ end }} class="bd-example m-0 border-0{{ with $class }} {{ . }}{{ end }}">
     {{- $input -}}
   </div>
   {{- end -}}