Add Unreal Engine style bezier edge

src/components/Edges/index.ts

@@ -1,4 +1,5 @@
 export { default as BezierEdge } from './BezierEdge';
-export { default as StepEdge } from './StepEdge';
+export { default as QuarticBezierEdge } from './QuarticBezierEdge';
 export { default as SmoothStepEdge } from './SmoothStepEdge';
+export { default as StepEdge } from './StepEdge';
 export { default as StraightEdge } from './StraightEdge';