Update TARDISTravelCommands.java

Merge request for Ticket #620.  /tardistravel [player], /tardistravel [biome], and /tardistravel dest [name] were each updated to require use of the Advanced Console + Disks in hard mode.  It directs the player to use the TARDIS Information System for help using Storage Disks.

If (easy mode) {
   Do the existing code.  No changes were made here.
} else {
   Hey there buddy, craft a Disk, Disks are cool!
}