update page-version.hbs

src/partials/page-versions.hbs

-{{#with page.versions}}
+{{!-- {{#with page.versions}} --}}
+{{#if page.component}}
 <div class="page-versions">
   <div class="backdrop"></div>
-  {{#with @root.page.componentVersion}}
-  <h2 class="title"><a href="{{{relativize ./url}}}">{{./title}}</a></h2>
-  {{/with}}
-  <button class="version-menu-toggle" title="Show other versions of page">v{{@root.page.componentVersion.displayVersion}}</button>
+  <h2 class="title"><a href="{{{relativize ./url}}}">{{page.component.title}}</a></h2>
+  <button class="version-menu-toggle" title="Show other versions of page">{{#if (or page.componentVersion.version (ne page.componentVersion.displayVersion 'default'))}}v{{page.componentVersion.displayVersion}}{{/if}}</button>
+  {{#with site.components.[0]}}
   <div class="version-menu">
-    {{#each this}}
+    {{#each ./versions}}
     <a class="version
-      {{~#if (eq ./version @root.page.version)}} is-current{{/if~}}
+      {{!-- {{~#if (eq ./version @root.page.version)}} is-current{{/if~}} --}}
+      {{~#if (and (eq .. @root.page.component) (eq this @root.page.componentVersion))}} is-current{{/if~}}
       {{~#if ./missing}} is-missing{{/if}}" href="{{{relativize ./url}}}">v{{./displayVersion}}</a>
     {{/each}}
   </div>
+  {{/with}}
 </div>
-{{/with}}
+{{/if}}
+{{!-- {{/with}} --}}