Remove hints for BT-36

[JanEmde]

I would like to suggest removing the hints for BT-36 (BT-36-Lot, BT-36-Lot-Unit, BT-36-Part and BT-36-Part-Unit). I think this hint creates more confusion than clarity.

First of all, the hint suggests that you have to fill in something, although this is not the case in all subtypes. Apart from this, it is also possible to specify just one fixed date and a period. Combinations of dates, durations and other information (BT-538) are also possible.

However, all of this is already very well covered by the forbidden rules, so in my view the hints are now pointless.