config.txt: move add.* 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 2ba7014..77e45e5 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -291,13 +291,7 @@
 
 include::config/core.txt[]
 
-add.ignoreErrors::
-add.ignore-errors (deprecated)::
-	Tells 'git add' to continue adding files when some files cannot be
-	added due to indexing errors. Equivalent to the `--ignore-errors`
-	option of linkgit:git-add[1].  `add.ignore-errors` is deprecated,
-	as it does not follow the usual naming convention for configuration
-	variables.
+include::config/add.txt[]
 
 alias.*::
 	Command aliases for the linkgit:git[1] command wrapper - e.g.

Documentation/config/add.txt

diff --git a/Documentation/config/add.txt b/Documentation/config/add.txt
new file mode 100644
index 0000000..4d753f0
--- /dev/null
+++ b/Documentation/config/add.txt
@@ -0,0 +1,7 @@
+add.ignoreErrors::
+add.ignore-errors (deprecated)::
+	Tells 'git add' to continue adding files when some files cannot be
+	added due to indexing errors. Equivalent to the `--ignore-errors`
+	option of linkgit:git-add[1].  `add.ignore-errors` is deprecated,
+	as it does not follow the usual naming convention for configuration
+	variables.