Add changelog entry

Signed-off-by: James Dinan <[email protected]>

content/backmatter.tex

@@ -648,6 +648,11 @@ \section{Version 1.6}
 The following list describes the specific changes in \openshmem[1.6]:
 \begin{itemize}
 %
+\item Added support for initialization and finalization routines to be called
+    multiple times, and added an initialization status query API
+    \FUNC{shmem\_query\_initialized}.
+\ChangelogRef{subsec:shmem_init, subsec:shmem_finalize, subsec:shmem_query_initialized}%
+%
 \item Added interleaved block transfer APIs \FUNC{shmem\_ibget} and
     \FUNC{shmem\_ibput}.
 \ChangelogRef{subsec:shmem_ibget, subsec:shmem_ibput}%