message: docs(readme): use correct key codes
diff: @@ -43,8 +43,8 @@ const BasicGraph = () => (
  - `style`: css style passed to the wrapper
  - `connectionLineType`: connection line type = `straight` or `bezier`
  - `connectionLineStyle`: connection style as svg attributes
  -- `deleteKeyCode`: default: `16`
  -- `selectionKeyCode`: default: `false`
  +- `deleteKeyCode`: default: `8` (delete)
  +- `selectionKeyCode`: default: `16` (shift)
  - `showBackground`: default: `true`
  - `backgroundGap`: gap size - default: `16`
  - `backgroundColor`: color of dots or lines - default: `#eee`
  