Reset Arduino by connecting vcc and gnd? A follow up question on my previous question, if a memory card reader can be used with three pins (digispark Attiny 85):

Can I read from a memory card with three pins?

Now I came up with another idea.
Since the USB connector or the VCC pin can power an Arduino my guess is that they are in parallel and the actual Arduino is connected to both.
Kind of like this very bad schematic made on my phone: (sorry for that)

Where the blue stuff is the Arduino chip.  

If that is true then adding the push button between VCC and GND with a resistor between should remove the power of the Arduino?
In that case I can have my code in setup() and use the pus button to reset the Arduino, and still have four pins to the memory card reader.  

Or is this wrong? What kind of resistor value do I need to make sure I don't short the USB connector but still have less resistance than the Arduino chip?
That is wrong. That is very, very wrong. That is one of the worst things you can do to a USB connection short of plugging it into the mains.

Do not even consider doing this.  Short circuits are never a good idea.