config.txt: move submodule.* to a separate file

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

diff --git a/Documentation/config.txt b/Documentation/config.txt
index aedc73f..966e82e 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -417,7 +417,7 @@
 
 include::config/stash.txt[]
 
-include::submodule-config.txt[]
+include::config/submodule.txt[]
 
 tag.forceSignAnnotated::
 	A boolean to specify whether annotated tags created should be GPG signed.

Documentation/config/submodule.txt

diff --git a/Documentation/submodule-config.txt b/Documentation/config/submodule.txt
similarity index 100%
rename from Documentation/submodule-config.txt
rename to Documentation/config/submodule.txt