Add decoupling capacitors to each MCU power pin

[ReikoR]

Each VDD/VDDA pin should have at least one 100nF capacitor.

[ReikoR]

Capacitors should not be connected in series to 3.3V.

[ReikoR]

Avoid having different units for same value components:

Also 100 nF capacitor per VDD/VDDA pin and one 4.7 uF capacitor would be enough.