Document the default source of template files.

Also explain a bit more about how the template option works.

Signed-off-by: Jon Loeliger <jdl@jdl.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-init-db.txt

@@ -14,7 +14,8 @@ SYNOPSIS
 OPTIONS
 -------
 --template=<template_directory>::
-	Provide the directory in from which templates will be used.
+	Provide the directory from which templates will be used.
+	The default template directory is `/usr/share/git-core/templates`.
 
 --shared::
 	Specify that the git repository is to be shared amongst several users.
@@ -22,9 +23,17 @@ OPTIONS
 
 DESCRIPTION
 -----------
-This simply creates an empty git repository - basically a `.git` directory
-and `.git/object/??/`, `.git/refs/heads` and `.git/refs/tags` directories,
-and links `.git/HEAD` symbolically to `.git/refs/heads/master`.
+This command creates an empty git repository - basically a `.git` directory
+with subdirectories for `objects`, `refs/heads`, `refs/tags`, and
+templated files.
+An initial `HEAD` file that references the HEAD of the master branch
+is also created.
+
+If `--template=<template_directory>` is specified, `<template_directory>`
+is used as the source of the template files rather than the default.
+The template files include some directory structure, some suggested
+"exclude patterns", and copies of non-executing "hook" files.  The
+suggested patterns and hook files are all modifiable and extensible.
 
 If the `$GIT_DIR` environment variable is set then it specifies a path
 to use instead of `./.git` for the base of the repository.
@@ -38,7 +47,6 @@ repository. When specifying `--shared` the config variable "core.sharedRepositor
 is set to 'true' so that directories under `$GIT_DIR` are made group writable
 (and g+sx, since the git group may be not the primary group of all users).
 
-
 Running `git-init-db` in an existing repository is safe. It will not overwrite
 things that are already there. The primary reason for rerunning `git-init-db`
 is to pick up newly added templates.