docs: add plugin setup guide

plugin/lib/commonlibf4/include/RE/P/PerkUtilities.h

@@ -0,0 +1,14 @@
+#pragma once
+
+namespace RE
+{
+	namespace PerkUtilities
+	{
+		inline void RemoveGrenadeTrajectory()
+		{
+			using func_t = decltype(&RemoveGrenadeTrajectory);
+			static REL::Relocation<func_t> func{ ID::PerkUtilities::RemoveGrenadeTrajectory };
+			return func();
+		}
+	}
+}