Adjust templates layout for hugo 0.146, potentially breaking change

layouts/_shortcodes/katex.html

@@ -0,0 +1,13 @@
+{{- if not (.Page.Scratch.Get "katex") -}}
+<!-- Include katex only first time -->
+<link rel="stylesheet" href="{{ "katex/katex.min.css" | relURL }}" />
+<script defer src="{{ "katex/katex.min.js" | relURL }}"></script>
+<script defer src="{{ "katex/auto-render.min.js" | relURL }}" onload="renderMathInElement(document.body);"></script>
+{{- .Page.Scratch.Set "katex" true -}}
+{{- end -}}
+
+<span {{- with .Get "class" }} class="{{ . }}"{{ end }}>
+  {{ with .Get "display" }}\[{{else}}\({{end}}
+  {{- .InnerDeindent -}}
+  {{ with .Get "display" }}\]{{else}}\){{end}}
+</span>