Cygwin: add /proc changes to release notes

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/release/3.0.4

@@ -5,6 +5,9 @@ What's new:
 What changed:
 -------------
 
+- Improve /proc/<PID>/cmdline and /proc/<PID>/stat handling to allow
+  all processes access to basic process information of foreign processes.
+
 
 Bug Fixes
 ---------

winsup/doc/new-features.xml

@@ -111,6 +111,12 @@ default and limited to exes/dlls on the same NTFS partition as the Cygwin
 installation.  For more information and how to enable, please refer to
 <xref linkend="ov-hi-process"></xref>.
 </para></listitem>
+
+<listitem><para>
+Improve /proc/&lt;PID&gt;/cmdline and /proc/&lt;PID&gt;/stat handling to allow
+all processes access to basic process information of foreign processes.
+</para></listitem>
+
 </itemizedlist>
 
 </sect2>