add fourth level air spells

spells/Fate4.tex

+\spell{Highest Blessing}% Name
+  {\mFate}% Spheres
+  {Wax}% Action
+  {\duplicated,\detailed,\distant}% Enhancements
+  {ambient noise}% Resist with
+  {targets receive \rollConv~\glspl{fp}}% Description
+  {
+    The caster extends their best wishes to a crowd, and anyone \spellArea\ away but still listening gains \rollConv~\glspl{fp} (or at least up to \spellArea\ people).
+    Noisier crowds can present a challenge, and raise the \gls{tn} significantly.
+  }
+

spells/fateAir4.tex

+\spell{Death Mist}% Name
+  {\mFate,\mAir}% Spheres
+  {Wane}% Action
+  {\duplicated,\detailed,\divergent}% Enhancements
+  {\roll{Charisma}{Vigilance}}% Resist with
+  {A stinking cloud covers \spellArea, inflicting \arabic{spelllevel}~\glspl{fatigue} to anyone in the area breathing it in, and removing \rollConv~\glspl{fp}}% Description
+  {
+    The caster simply laughs like a spoilt child done something awful.
+    A fetid mist in the form of Sylf, mother of monsters, envelops \spellArea\ targets.
+    They immediately lose \rollConv~\glspl{fp}, and anyone breathing the mist in gains \arabic{spelllevel}~\glspl{fatigue}.
+  }
+