If you mean by "over" between Vcc and Gnd, there is already a 100nF capacitor. I didn't draw it in the circuit. It is connected between the output of the 7805 and Gnd.
That is nice, but not it, you must have 100nF soldered directly, using the shortest leads possible between Vcc and Gnd on each and every chip in your circuit.

Rrik