Add Power connector pinout Documentation

PowerConnector.txt

+=== Cable, Control end ===
+                     V
+(brown) Status  4  o   o  1  GND (blue)
+(green) 5V      3  o   o  2  12V (orange)
+
+=== USV Connector ===
+
+ Status   5V     12V    GND
+    X      X      X      X
+(brown)(green)(orange)(blue)
\ No newline at end of file