Update o1p01-clear-purpose.html

added changes from proposal 2

Link - https://docs.google.com/document/d/1xnoNFwfjJZbfadFiU-qOW49n4-gODbd_4ff5UDyYFTM/edit?tab=t.0#heading=h.a6gleb37y36o

Author: RashmiKatakwar

design-guide/o1p01-clear-purpose.html

@@ -52,6 +52,10 @@ How it Helps
     a video. They can tell by the video title that this video has the
     information they need.
   p>
+  <p>
+    For this pattern to be useful, each page must have a clear purpose. It works best when each page covers
+    a single unifying topic. (See <a>4.3.2a>4.3.2 for more details.)
+  p>
 section>
 <section>
   <h5 class="coga-5">More Detailsh5>