build(docs-infra): expose deprecated status on items more clearly (#25750)

PR Close #25750

aio/tools/transforms/templates/api/base.template.html

@@ -16,12 +16,15 @@
     </script>
     {% for crumb in doc.breadCrumbs %}{% if not loop.last %} {$ breadcrumbDelimiter() $} {% if crumb.path %}<a href="{$ crumb.path $}">{$ crumb.text $}</a>{% else %}{$ crumb.text $}{% endif %}{% endif %}{% endfor %}
   </div>
+  {% block header %}
   <header class="api-header">
     <h1>{$ doc.name $}</h1>
     <label class="api-type-label {$ doc.docType $}">{$ doc.docType $}</label>
+    {% if doc.deprecated !== undefined %}<label class="api-status-label deprecated">deprecated</label>{% endif %}
     {% if doc.security !== undefined %}<label class="api-status-label security">security</label>{% endif %}
     {% if doc.pipeOptions.pure === 'false' %}<label class="api-status-label impure-pipe">impure</label>{% endif %}
   </header>
+  {% endblock %}
   <aio-toc class="embedded"></aio-toc>
 
   <div class="api-body">