message: change 'smoothedge' to correct 'smoothstep' in README
diff: @@ -306,7 +306,7 @@ You can find an example with different edges in the [edges example](https://reac
  ## Edge Types & Custom Edges
  -The basic edge types are `default` (bezier), `straight`, `step` and `smoothedge`. The default `edgeTypes` object looks like this:
  +The basic edge types are `default` (bezier), `straight`, `step` and `smoothstep`. The default `edgeTypes` object looks like this:
  ```javascript
  {
  