PNP high side switching with 100 mA load
When switch closed 100R resistor limits capacitor discharge current through switch to reduce switch wear.
When switch is closed, base of BC327 is pulled down to approx 11.3V pulling about 1.5mA out of the transistor's base. This is sufficient base current to cater for your 100mA load. Minimum hFE of BC327 is 100 which is higher than the 2N3906's minimum hFE. Q1 is configured in common emitter mode.
When switch is closed, base of BC548 is pulled almost to ground switching off the LED. BC548 is configured in emitter follower mode.
When switch is opened, base of BC327 is pulled up to about 11.9V switching off the BC327 and enabling its collector to fall to 0V. Simmultaneously R2 &amp; R4 now supply base current to Q2 switching on the LED.