Merge branch 'bw/config-refer-to-gitsubmodules-doc'

Docfix.

* bw/config-refer-to-gitsubmodules-doc:
  docs: link to gitsubmodules

Documentation/config.txt

@@ -3328,12 +3328,13 @@ submodule.<name>.ignore::
 submodule.<name>.active::
 	Boolean value indicating if the submodule is of interest to git
 	commands.  This config option takes precedence over the
-	submodule.active config option.
+	submodule.active config option. See linkgit:gitsubmodules[7] for
+	details.
 
 submodule.active::
 	A repeated field which contains a pathspec used to match against a
 	submodule's path to determine if the submodule is of interest to git
-	commands.
+	commands. See linkgit:gitsubmodules[7] for details.
 
 submodule.recurse::
 	Specifies if commands recurse into submodules by default. This