[m-rev.] for review: rename NEWS -> NEWS.md

[Julien Fischer]

I originally proposed this in Februrary 2018 and there were no objections.
The request for review is really an opportunity for any such last 
objections. I intend to commit this tomorrow in the absence of any 
objections.

------------------------------

Rename NEWS -> NEWS.md.

NEWS:
     As above.

README.md:
RELEASE_NOTES:
bindist/Mmakefile:
compiler/notes/coding_standards.html:
compiler/notes/developer_intro.html:
     Conform to the above change.

Julien.

diff --git a/README.md b/README.md
index eb7d44c20..bc9a28612 100644
--- a/README.md
+++ b/README.md
@@ -61,7 +61,7 @@ Specific information is contained in individual README files:
  ## Other information

  See the current [release notes](RELEASE_NOTES) for the latest stable release.
-The [news](NEWS) file lists any recent changes.
+The [news](NEWS.md) file lists any recent changes.
  The [history](HISTORY) file is relevant
  if you want to find out more about the past development of Mercury.
  The [limitations](LIMITATIONS.md) file lists some ways
diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index 8bc1a838e..d25eb6d40 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -13,7 +13,7 @@ traditional logic programming syntax, but also allows the
  syntactic convenience of user-defined functions, smoothly integrating
  logic and functional programming into a single paradigm.

-For a list of what's new in this release, see the NEWS file.
+For a list of what's new in this release, see the NEWS.md file.

  The main features of Mercury are:

diff --git a/bindist/Mmakefile b/bindist/Mmakefile
index e5f9e5a18..717c0a641 100644
--- a/bindist/Mmakefile
+++ b/bindist/Mmakefile
@@ -30,7 +30,7 @@ UTILS		= $(INSTALL_PREFIX)/bin/mkinit$(EXT_FOR_EXE) \
  		  $(INSTALL_PREFIX)/bin/vpath_find

  README_ETC	= ../COPYING ../COPYING.LIB ../HISTORY ../LIMITATIONS.md \
-		  ../NEWS ../RELEASE_NOTES ../BUGS ../WORK_IN_PROGRESS \
+		  ../NEWS.md ../RELEASE_NOTES ../BUGS ../WORK_IN_PROGRESS \
  		  ../TODO ../VERSION ../README.* ../LICENSE

  INSTALL_SCRIPTS	= ../scripts/c2init ../scripts/mmc \
diff --git a/compiler/notes/coding_standards.html b/compiler/notes/coding_standards.html
index b096e58af..cf845654a 100644
--- a/compiler/notes/coding_standards.html
+++ b/compiler/notes/coding_standards.html
@@ -41,7 +41,7 @@ saying what the field represents.
  Any user-visible changes such as new compiler options or new features
  should be documented in the appropriate section(s) of the Mercury documentation
  (usually the Mercury User's Guide and/or the Mercury Reference Manual).
-Any major new features should be documented in the NEWS file,
+Any major new features should be documented in the NEWS.md file,
  as should even small changes to the library interface,
  or anything else that might cause anyone's existing code to break.
  <p>
diff --git a/compiler/notes/developer_intro.html b/compiler/notes/developer_intro.html
index 5ea810265..bb476b78b 100644
--- a/compiler/notes/developer_intro.html
+++ b/compiler/notes/developer_intro.html
@@ -89,7 +89,7 @@ only the default grade (probably asm_fast.gc).
  <p>
  A good way to do this is to create (or modify an existing) Mmake.params file
  in the top-level of the mercury distribution
-(in the same directory as README and NEWS).
+(in the same directory as README and NEWS.md).
  Mmake.params is used to set local workspace options,
  and is very useful for overriding default mmake settings.
  Add the line