doc/changes.src: document ELF TLS

Add ELF TLS to the release notes.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/doc/changes.src b/doc/changes.src
index 02446df..2d8b850 100644
--- a/doc/changes.src
+++ b/doc/changes.src
@@ -17,6 +17,8 @@
 \b The argument to \c{%use} is no longer macro-expanded.  Use
   \c{%[...]} if macro expansion is desired.
 
+\b Support for thread-local storage in ELF32 and ELF64.  See \k{elftls}.
+
 
 \S{cl-2.05.01} Version 2.05.01