Add zbaring install command in README.md

README.md

@@ -4,6 +4,10 @@
 # Prerequisit
 `PHP 7.3 or greater`
 
+To read QR code the command 'zbaring' is necessary
+To install the command on Debian : 
+`sudo apt install zbar-tools`
+
 ## PHP Modules:
 - fileinfo (php_finfo)
 - pdf (php_pdf)