[css-text-3] Editorial adjustement to how UAX14 is presented

Closes #5068

Author: frivoal

css-text-3/Overview.bs

@@ -2387,10 +2387,13 @@ Text Processing</h3>
   </ul>
 
   <div class="note">
-    <p>Note: Further information on line breaking conventions can be found in
-      [[JLREQ]] and [[JIS4051]] for Japanese,
-      [[CLREQ]] and [[ZHMARK]] for Chinese, and
-      in [[UAX14]] for all scripts in Unicode.
+    <p>
+      Note: [UAX14] defines a baseline behavior
+      for line breaking for all scripts in Unicode,
+      which is expected to be further tailored.
+      Further information on line breaking conventions
+      can be found in [JLREQ] and [JIS4051] for Japanese,
+      [CLREQ] and [ZHMARK] for Chinese.
       See also the
       <a href="https://www.w3.org/International/">Internationalization Working Group</a>’s
       <a href="https://www.w3.org/TR/typography/#blocks_paragraphs">Typography Index</a> [[TYPOGRAPHY]]