Add description for configuration variables

config.conf

@@ -1,4 +1,15 @@
 #!/usr/bin/env bash
+#####################
+# This is the configuration file for the archinstall script.
+# Please define here stuff that is needed to execute the scripts correctly.
+# For example:
+# HDD      the storage device where the OS should be installed
+# ROOTPART the partition where the Root-partition should be located
+# BOOTPART the partition where the Boot-partition should be located
+# HOST     the hostname of the OS
+# USER     the username for the primary user
+# PWD      the password for the primary user and root account
+#####################
 readonly HDD="/dev/sda"
 readonly ROOTPART="/dev/sda2"
 readonly BOOTPART="/dev/sda1"