MINOR Updated documentation.html to have 3.5 and 3.6 previous release doc links (#14510)

Reviewers: Luke Chen <showuon@gmail.com>, kpatelatwork <kpatel@confluent.io>

docs/documentation.html

@@ -33,7 +33,7 @@
     <!--//#include virtual="../includes/_docs_banner.htm" -->
     
     <h1>Documentation</h1>
-    <h3>Kafka 3.4 Documentation</h3>
+    <h3>Kafka 3.6 Documentation</h3>
     Prior releases: <a href="/07/documentation.html">0.7.x</a>, 
                     <a href="/08/documentation.html">0.8.0</a>, 
                     <a href="/081/documentation.html">0.8.1.X</a>, 
@@ -58,6 +58,8 @@
                     <a href="/31/documentation.html">3.1.X</a>.
                     <a href="/32/documentation.html">3.2.X</a>.
                     <a href="/33/documentation.html">3.3.X</a>.
+                    <a href="/34/documentation.html">3.4.X</a>.
+                    <a href="/35/documentation.html">3.5.X</a>.
 
    <h2 class="anchor-heading"><a id="gettingStarted" class="anchor-link"></a><a href="#gettingStarted">1. Getting Started</a></h2>
       <h3 class="anchor-heading"><a id="introduction" class="anchor-link"></a><a href="#introduction">1.1 Introduction</a></h3>