Minor doc improvement in nt/INSTALL.W64

[Alain Schneble]

Hello

Once again, I stumbled across the newline issue when running autogen.sh
on MS Windows, caused by a wrong GIT/core.autocrlf setting.  In this
regard, I think it would be worth to refine a passage in nt/INSTALL.W64
as follows:

>From dd2f6178176a78d4440776addb68c842a7be58dc Mon Sep 17 00:00:00 2001
From: Alain Schneble <address@hidden>
Date: Sat, 20 Aug 2016 21:01:04 +0200
Subject: [PATCH] Refine comment on GIT core.autocrlf in nt/INSTALL.W64

---
 nt/INSTALL.W64 | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/nt/INSTALL.W64 b/nt/INSTALL.W64
index e109c6f..970bb20 100644
--- a/nt/INSTALL.W64
+++ b/nt/INSTALL.W64
@@ -85,7 +85,14 @@ in your MSYS2 environment with:
 The autocrlf feature of Git may interfere with the configure file, so it is
 best to disable this feature by running the command:
 
-  git config core.autocrlf false
+  git config --global core.autocrlf false
+
+The --global (or --system) option is required as the configuration
+variable must be set before cloning the GIT repository.
+Alternatively, to use a repository-local variable, specify --config
+option to git clone:
+
+  git clone --config core.autocrlf=false ...
 
 * Get the Emacs source code
 
-- 
2.8.1.windows.1

Do you agree?

Thanks,
Alain