Update notes for version 1.0.9

Bowgun sigil tutorial placed;
Boiler Quest hint on map improved to be marked until the Boiler is powered up;
Death sound playing when switching level on the Eurynomous Pit;
Spikes on Dead Complex correctly animated;
Impossible to get Monolyth on Murky Pipeworks fixed;
Frozen worm shown on Eurynomous Pit background as expected;
Fix to some wall being possible to just walk through;