[TASK] Change header, make link conditional

Resources/Private/Partials/Feature/ShowFeature.html

 <div class="container">
     <div class="row">
         <div class="col-8">
-            <h1 class="">{feature.header}</h1>
+            <h2 class="">{feature.header}</h2>
             <p>Introduced in version {feature.typo3releaseminorversion.version} <f:if condition="{settings.showFeatureArea}"><f:link.typolink parameter="{feature.featureArea.page}">Feature Area</f:link.typolink></f:if></p>
             <f:format.html>{feature.description}</f:format.html>
-            <p><f:link.typolink parameter="{feature.link}" class="btn btn-primary mr-3" target="_blank">Documentation</f:link.typolink></p>
+            <f:if condition="{feature.link}">
+                <p><f:link.typolink parameter="{feature.link}" class="btn btn-primary mr-3" target="_blank">Documentation</f:link.typolink></p>
+            </f:if>
         </div>
         <div class="col-4">
             <f:for each="{feature.images}" as="image">
@@ -12,4 +14,4 @@
             </f:for>
         </div>
     </div>
-</div>
\ No newline at end of file
+</div>