[css-text-3] remove carriage return from document white space

Related to w3c#855

Author: frivoal

css-text-3/Overview.bs

@@ -592,7 +592,7 @@ Characters and Letters</h3>
     <a href="https://www.w3.org/TR/CSS21/visuren.html#anonymous">9.2.2.1</a></p>
 
   <p>
-    Form feeds (U+000C) and carriage returns (U+000D)
+    Form feeds (U+000C)
     (that are not <a>segment breaks</a>)
     are rendered as a zero-width space (U+200B). <!-- thus can disrupt shaping -->
     Control characters (<a>Unicode category</a> <code>Cc</code>)
@@ -619,7 +619,7 @@ Characters and Letters</h3>
       Note that the set of characters considered <a>document white space</a> (part of the document content)
       and that considered syntactic white space (part of the CSS syntax)
       are not necessarily identical.
-      However, since both include spaces (U+0020), tabs (U+0009), line feeds (U+000A), and carriage returns (U+000D)
+      However, since both include spaces (U+0020), tabs (U+0009), and line feeds (U+000A)
       most authors won't notice any differences.
 
     <h4 id="white-space-phase-1">Phase I: Collapsing and Transformation</h4>