Yes - Form 502CR should be generated in your MD return for credit for taxes paid to DE.
Some questions: Did you actually pay taxes to DE or did you get all of the withholding back? The tax appears on line 47 of DE Form 200-02. If you got all of your DE withholding back, you won't get a credit.
Since you have two states in your return, did you prepare the nonresident state (DE) first? This way the credit for taxes paid in DE flow properly to your MD return.