Documentation: clarify pager configuration

The unwary user may not know how to disable the -FRSX options.

Signed-off-by: Jonathan Nieder <jrnieder@uchicago.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -358,8 +358,13 @@ core.editor::
 	`EDITOR` environment variables and then finally `vi`.
 
 core.pager::
-	The command that git will use to paginate output.  Can be overridden
-	with the `GIT_PAGER` environment variable.
+	The command that git will use to paginate output.  Can
+	be overridden with the `GIT_PAGER` environment
+	variable.  Note that git sets the `LESS` environment
+	variable to `FRSX` if it is unset when it runs the
+	pager.  One can change these settings by setting the
+	`LESS` variable to some other value or by giving the
+	`core.pager` option a value such as "`less -+FRSX`".
 
 core.whitespace::
 	A comma separated list of common whitespace problems to

Documentation/git.txt

@@ -497,7 +497,8 @@ other
 'GIT_PAGER'::
 	This environment variable overrides `$PAGER`. If it is set
 	to an empty string or to the value "cat", git will not launch
-	a pager.
+	a pager.  See also the `core.pager` option in
+	linkgit:git-config[1].
 
 'GIT_SSH'::
 	If this environment variable is set then 'git-fetch'