help written

git_update.sh

@@ -1,12 +1,32 @@
 #!/bin/bash
 summary="$0 [options] <repo>"
-
 ref=main
 dst='.'
 nonempty_target=false
 use_home=false
 be_aggressive=false
 
+Help(){
+	echo "
+NAME
+    git_update.sh
+SYNOPSIS
+    git_update.sh [-h] [-r ref] [-d dest] [-H] [-N] [-a] repository
+OPTIONS
+    -h prints the help. 
+	-r specifies the reference to the commit to be synchronized. It can be a tag or a branch. By default, it is the last commit of branch main.
+	-d specifies the destination of the clone or update. If non-empty, -N must be specified. 
+	-H 
+	-N indicates that the destination is non-empty. The files that do not conflict and if it is an update, are not committed, will be kept. 
+	-a specifies that the aggressive option of git clean must be used. git clean is called wen -N is not specified. 
+	If the repository to be cloned is local, and its path is passed as a relative path, the path should start from the destination. 
+	To avoid mistakes, absolute paths are advised.
+
+DESCRIPTION
+	This script will replace the destination with the wanted commit of a git repository. The history is not preserved but tags are.
+	The git commands have been chosen so as to minimize the memory and bandwidth usages."
+}
+
 while getopts ":hr:d:NHa" option; do
    case $option in
       h) # display Help