add air3 spell

spells/air3.tex

+\spell{Putrid Visage}% Name
+  {\mWater, \mFate}% Spheres
+  {Wane}% Action
+  {\detailed, \duplicated}% Enhancements
+  {Deceit}% Skill
+  {Stinking cloud covers \spellArea, inflicting \arabic{spelllevel}~\glspl{fatigue} to anyone in the area}% Description
+  {
+    The air pollutes, growing dark and smoggy, in the exact shape of the caster's face with a maniacal grin.
+    The miasma covers \spellArea, and anyone breathing in the vapours suffers \arabic{spelllevel}~\glspl{fatigue}.
+  }
+