Updates for release_docs/NEWSLETTER.txt. (HDFGroup#4423)

bin/release

@@ -455,7 +455,7 @@ cp -p Makefile.dist Makefile
 
 # Update README.md and release_docs/RELEASE.txt with release information in
 # line 1.
-for f in README.md release_docs/RELEASE.txt; do
+for f in README.md release_docs/RELEASE.txt release_docs/NEWSLETTER.txt; do
     echo "HDF5 version $VERS released on $release_date" >$f.x
     sed -e 1d $f >>$f.x
     mv $f.x $f

release_docs/NEWSLETTER.txt

@@ -1,18 +1,9 @@
-Release of HDF5 1.14.4 Library and Tools is now available from the HDF5 Releases page.
+HDF5 version 1.15.0 currently under development
 
-This is a maintenance release with a few changes and updates:
+Features included for the next major release:
 ----------------------------------------------------------------------------
 
-* Added support for _Float16 16-bit floating-point datatype
-
-  Support for the 16-bit floating-point _Float16 C type has been added to
-  HDF5. On platforms where this type is available, this can enable more
-  efficient storage of floating-point data when an application doesn't
-  need the precision of larger floating-point datatypes. It can also allow
-  for improved performance when converting between 16-bit floating-point
-  data and data of another HDF5 datatype.
-
-  (GitHub #4065, #2154)
+*
 
 ----------------------------------------------------------------------------
 Please see the full release notes for detailed information regarding this release,