[FEATURE] Show introcuced text only if there is a version

https://git-t3o.typo3.org/t3o/typo3_roadmap/issues/6

Resources/Private/Partials/Feature/ShowFeature.html

@@ -2,7 +2,9 @@
     <div class="row">
         <div class="col-8">
             <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:if condition="{feature.typo3releaseminorversion.version}">
+                <p class="alert alert-info text-center">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:if>
             <f:format.html>{feature.description}</f:format.html>
             <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>