Allow to spread props at the start

[TrySound]

The use case is flow which warns about inexact spread. My template looks
like this and I need to spread props before any other prop.

const template = (code, options, state) => `
// @flow
// Generated from ${state.filePath}

import * as React from "react";

type Props = {
  size?: string | number,
  fill?: string
};

const style = {
  display: "block",
  flex: "0 0 auto",
};

export const ${state.componentName} = ({ size, fill, ...props }: Props) => {
  return (
    ${code}
  );
};
`;

[codecov]

Codecov Report

Merging #166 into master will increase coverage by 0.15%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #166      +/-   ##
==========================================
+ Coverage   88.73%   88.88%   +0.15%     
==========================================
  Files          26       26              
  Lines         435      441       +6     
  Branches       79       82       +3     
==========================================
+ Hits          386      392       +6     
  Misses         47       47              
  Partials        2        2

Impacted Files	Coverage Δ
packages/core/src/h2x/expandProps.js	100% <100%> (ø)	⬆️
packages/core/src/plugins/h2x.js	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update d1ae730...e368f67. Read the comment docs.

[gregberge]

I understand the use case, code looks great. Can you update all relative readme please?

[TrySound]

I'm not sure how to make it work with cli. Currently svgr has --no-expand-props option. Should I add --expand-props?

Ideally it should be enum like start | end | none

[TrySound]

So how would you like to go?

[gregberge]

You are right, so it is OK like that. We have to change it in the next major.