Update release note template for 8.14 (#12371)

all/src/main/templates/release-notes.html

@@ -83,8 +83,8 @@
             enhancements. Below is a list of the most notable changes:</p>
 
         <ul>
-		<li></li>
-        </ul>
+		<li>Reworked and cleaned up client-side TabSheet and Accordion</li>
+       </ul>
 
         </p>
 
@@ -99,8 +99,7 @@
         <h2 id="incompatible">Incompatible or Behavior-altering Changes in @version-minor@</h2>
 
         <ul>
-            <li></li>
-            <li></li>
+            <li>Deprecating Flash component</li>
         </ul>
 
         <h2>For incompatible or behavior-altering changes in 8.13, please see <a href="https://vaadin.com/download/release/8.13/8.13.0/release-notes.html#incompatible">8.13 release notes</a></h2>