fix: missing RaycasterHelper index export (#390)

Author: abernier

src/index.ts

@@ -246,6 +246,7 @@ export * from './lines/Line2'
 export * from './lines/LineMaterial'
 export * from './lines/LineSegments2'
 export * from './helpers/LightProbeHelper'
+export * from './helpers/RaycasterHelper'
 export * from './helpers/VertexTangentsHelper'
 export * from './helpers/PositionalAudioHelper'
 export * from './helpers/VertexNormalsHelper'