Merge branch 'pr-155'

Refs #154
Refs #155

Author: joschi

core/src/main/java/com/qdesrame/openapi/diff/core/output/HtmlRender.java

@@ -358,7 +358,10 @@ private ContainerTag li_changedParam(ChangedParameter changeParam) {
       return li_deprecatedParam(changeParam);
     }
     boolean changeRequired = changeParam.isChangeRequired();
-    boolean changeDescription = changeParam.getDescription().isDifferent();
+    boolean changeDescription =
+        Optional.ofNullable(changeParam.getDescription())
+            .map(ChangedMetadata::isDifferent)
+            .orElse(false);
     Parameter rightParam = changeParam.getNewParameter();
     Parameter leftParam = changeParam.getNewParameter();
     ContainerTag li = li().withText(changeParam.getName() + " in " + changeParam.getIn());