Describe the bug
Script forces to erase all partition layout on disk, even if there's sufficient unused space on partition table, in a scenario where existing Windows would like to be kept intact for dual boot

To Reproduce
Steps to reproduce the behavior:

1. On your Windows PC, shrink the Windows Data partition and make available a large free space in partition table
2. Download Arch Iso and boot with it.
3. Use the easy-arch script, at least step, it will ask you to confirm deleting all your partitions

Expected behavior
Present dialog that new partitions will be created for boot and encrypted root, use default size for boot ie 2gb and allocate rest of free space to root.