Resolved issues with Pyro Schematics + a little tidying up.
- PMOS upside down
- TVS diode for ESD (ESD8V0R1B-02LS at 2.18p each, 1.91p each (25-99), 1.72p each (100-249))
- Replaced Heirachial Pins with CONN_2
- !PY_CHK pins added (check for pyro presence)