init/clone: remove short option -L and document --separate-git-dir

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-clone.txt

@@ -12,7 +12,7 @@ SYNOPSIS
 'git clone' [--template=<template_directory>]
 	  [-l] [-s] [--no-hardlinks] [-q] [-n] [--bare] [--mirror]
 	  [-o <name>] [-b <name>] [-u <upload-pack>] [--reference <repository>]
-	  [--separate-git-dir|-L <git dir>]
+	  [--separate-git-dir <git dir>]
 	  [--depth <depth>] [--recursive|--recurse-submodules] [--] <repository>
 	  [<directory>]
 
@@ -177,7 +177,6 @@ objects from the source repository into a pack in the cloned repository.
 	repository does not have a worktree/checkout (i.e. if any of
 	`--no-checkout`/`-n`, `--bare`, or `--mirror` is given)
 
--L=<git dir>::
 --separate-git-dir=<git dir>::
 	Instead of placing the cloned repository where it is supposed
 	to be, place the cloned repository at the specified directory,

Documentation/git-init-db.txt

@@ -8,7 +8,7 @@ git-init-db - Creates an empty git repository
 
 SYNOPSIS
 --------
-'git init-db' [-q | --quiet] [--bare] [--template=<template_directory>] [--shared[=<permissions>]]
+'git init-db' [-q | --quiet] [--bare] [--template=<template_directory>] [--separate-git-dir <git dir>] [--shared[=<permissions>]]
 
 
 DESCRIPTION

Documentation/git-init.txt

@@ -9,7 +9,7 @@ git-init - Create an empty git repository or reinitialize an existing one
 SYNOPSIS
 --------
 'git init' [-q | --quiet] [--bare] [--template=<template_directory>]
-	  [--separate-git-dir|-L <git dir>]
+	  [--separate-git-dir <git dir>]
 	  [--shared[=<permissions>]] [directory]
 
 
@@ -54,7 +54,6 @@ current working directory.
 Specify the directory from which templates will be used.  (See the "TEMPLATE
 DIRECTORY" section below.)
 
--L=<git dir>::
 --separate-git-dir=<git dir>::
 
 Instead of initializing the repository where it is supposed to be,