Add comment concerning command folding

Fix vim-latex/vim-latex#189

doc/latex-suite.txt

@@ -1972,6 +1972,10 @@ NOTE: It is very difficult to fold commands reliably because it is very
           }
 <     will not be folded. This is a bug which is very difficult to fix.
       
+      Similarly, a command fold will stop at the first line containing a '}',
+      even if this brace does not correspond to the opening brace of the
+      command.
+      
       
 See also advanced fold settings [|ls_a_co|].
 

doc/latex-suite.xml

@@ -2465,6 +2465,10 @@ and some more text
 }</programlisting>
       will not be folded. This is a bug which is very difficult to fix.
      </para>
+     <para>
+      Similarly, a command fold will stop at the first line containing a '}',
+      even if this brace does not correspond to the opening brace of the command.
+     </para>
     </note>
     <para>
      See also <link linkend="fold-setting-advanced">advanced fold