Add 'needs LaTeX' meta for pages where LaTeX is needed for Bergamot

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

layouts/partials/head.html

@@ -58,6 +58,8 @@
     {{ end }}
 
     {{ if .Params.bergamot }}
+    <!-- Ensure later scripts keep the KaTeX CSS even if the page has no LaTeX !-->
+    <meta name="needs-latex">
     <!-- Code to support the Bergamot JS widget -->
     <script defer src="{{ .Site.Params.katexJsUrl }}" crossorigin="anonymous"></script>
     {{ $katexComponentJs := resources.Get "js/katex-component.js" | resources.Minify }}