Use anchor heading attribute instead of bookHeadingAnchor

exampleSite/content.en/_index.md

@@ -1,12 +1,11 @@
 ---
 title: Introduction
-bookHeadingAnchor: false
 layout: landing
 ---
 
 <div class="book-hero">
 
-# HUGO BOOK
+# HUGO BOOK {anchor=false}
 [Hugo](https://gohugo.io) documentation theme as simple as plain book
 
 {{< badge style="info" title="Badge" value="Value" >}} {{< badge style="default" title="Badge" value="Value" >}}

layouts/_markup/render-heading.html

@@ -1,6 +1,6 @@
-<h{{ .Level }} id="{{ .Anchor }}" {{- with .Attributes.class }} class="{{ . }}" {{- end }}>
+<h{{ .Level }} id="{{ .Anchor }}" {{- with .Attributes.class -}}class="{{ . }}"{{- end -}}>
-  {{ .Text }}
+  {{- .Text -}}
-  {{ if default true .Page.Params.bookHeadingAnchor }}
+  {{- if default true .Attributes.anchor }}
   <a class="anchor" href="#{{ .Anchor }}">#</a>
-  {{ end }}
+  {{- end -}}
 </h{{ .Level }}>