Add notice about tasks defined in method building blocks

src/app/development-processes/method-elements/method-elements.component.html

@@ -5,6 +5,11 @@
 </div>
 
 <main role="main" class="container">
+  <div class="my-3 alert alert-info">
+    All method elements, except for tasks, are defined in the presented
+    sections. Tasks are directly defined while creating method building blocks.
+  </div>
+
   <app-list-wrapper listTitle="Method Elements">
     <div results class="list-group">
       <a