message: refactor(grid): add className, styles and default values
diff: import React, { memo } from 'react';
  import { useStoreState } from 'easy-peasy';
  -
  -const GridRenderer = memo(({gap = 32}) => {
  +import classnames from 'classnames';
  +
  +const baseStyles = {
  + position: 'absolute',
  + top: 0,
  + left: 0
  +};
  +
  +const GridRenderer = memo(({
  + gap = 24, strokeColor = '#999', strokeWidth = 0.1, styles,
  + className
  +}) => {
  const {
  width,
  height,
  transform: [x, y, scale],
  } = useStoreState(s => s);
  + const gridClasses = classnames('react-flow__grid', className);
  const scaledGap = gap * scale;
  const xStart = x % scaledGap;
  @@ -22,8 +33,18 @@ const GridRenderer = memo(({gap = 32}) => {
  const path = [...xValues, ...yValues].join(' ');
  return (
  - <svg width={width} height={height} style={{position: 'absolute', top: 0, left: 0}}>
  - <path fill="none" stroke="black" strokeWidth={.1} d={path} />
  + <svg
  + width={width}
  + height={height}
  + style={{ ...baseStyles, ...styles }}
  + className={gridClasses}
  + >
  + <path
  + fill="none"
  + stroke={strokeColor}
  + strokeWidth={strokeWidth}
  + d={path}
  + />
  </svg>
  );
  });
  