Write a Python program that asks the user to enter two integers: one for the number of rows and one for the number of columns. The program should then produce a text-based drawing where each position in the drawing is randomly determined with equal probability to be either a "*" or a "-". For example, with 4 rows and 6 columns, the drawing might look like this:
**-*-*
--**--
-*--*-
---*-*