readline: make description more enlightening and fix indentation

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/readline/Config.in

@@ -2,4 +2,6 @@ config BR2_PACKAGE_READLINE
 	bool "readline"
 	select BR2_PACKAGE_NCURSES
 	help
-	    Enable GNU readline support?
+	  The GNU Readline library provides a set of functions for use
+	  by applications that allow users to edit command lines
+	  as they are typed in.