Documentation: don't assume git-sh-setup and git-parse-remote are in PATH

When git-parse-remote and git-sh-setup are not installed in
$(bindir) anymore, the shell script library won't be found on
user's $PATH in general.

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

Documentation/git-parse-remote.txt

@@ -8,7 +8,7 @@ git-parse-remote - Routines to help parsing remote repository access parameters
 
 SYNOPSIS
 --------
-'. git-parse-remote'
+'. "$(git --exec-path)/git-parse-remote"'
 
 DESCRIPTION
 -----------

Documentation/git-sh-setup.txt

@@ -7,7 +7,7 @@ git-sh-setup - Common git shell script setup code
 
 SYNOPSIS
 --------
-'git-sh-setup'
+'. "$(git --exec-path)/git-sh-setup"'
 
 DESCRIPTION
 -----------