docs: Move "news" to "changelog"

Move the list of changes for each release up under the release notes
section, in a new subsection entitled "Changelog".  This makes a
little more sense than having a standalone "News" section, which was
really just a throwback to the old standlaone NEWS text file, anyway.

Signed-off-by: Jeff Squyres <jeff@squyres.com>

Author: jsquyres

docs/Makefile.am

@@ -1,7 +1,7 @@
 #
 # Copyright (c) 2022 Cisco Systems, Inc.  All rights reserved.
+# Copyright (c) 2023-2024 Jeffrey M. Squyres.  All rights reserved.
 #
-# Copyright (c) 2023      Jeffrey M. Squyres.  All rights reserved.
 # $COPYRIGHT$
 #
 # Additional copyrights may follow
@@ -41,6 +41,7 @@ IMAGE_SOURCE_FILES = \
 RST_SOURCE_FILES   = \
         $(srcdir)/*.rst \
         $(srcdir)/release-notes/*.rst \
+        $(srcdir)/release-notes/changelog/*.rst \
         $(srcdir)/installing-open-mpi/*.rst \
         $(srcdir)/installing-open-mpi/*/*.rst \
         $(srcdir)/features/*.rst \
@@ -51,7 +52,6 @@ RST_SOURCE_FILES   = \
         $(srcdir)/app-debug/*.rst \
         $(srcdir)/developers/*.rst \
         $(srcdir)/license/*.rst \
-        $(srcdir)/news/*.rst \
         $(srcdir)/man-openmpi/*.rst \
         $(srcdir)/man-openmpi/man*/*.rst \
         $(srcdir)/man-openshmem/*.rst \

docs/index.rst

@@ -80,6 +80,5 @@ Table of contents
    contributing
    license/index
    history
-   news/index
    man-openmpi/index
    man-openshmem/index

docs/news/index.rst

@@ -0,0 +1,17 @@
+Changelog
+=========
+
+This section contains the main features as well as overviews of
+specific bug fixes (and other actions) for each version of Open MPI
+since v1.0.0.
+
+.. toctree::
+   :maxdepth: 1
+
+   v5.0.x
+   v4.1.x
+   v4.0.x
+   v3.1.x
+   v3.0.x
+   v2.x
+   v1.x