message: docs: added bundle size info badge
diff: [![CDNJS](https://img.shields.io/cdnjs/v/vee-validate.svg)](https://cdnjs.com/libraries/vee-validate/)
  [![npm](https://img.shields.io/npm/dm/vee-validate.svg)](https://npm-stat.com/charts.html?package=vee-validate)
  [![npm](https://img.shields.io/npm/v/vee-validate.svg)](https://www.npmjs.com/package/vee-validate)
  +[![Bundle Size](https://badgen.net/bundlephobia/minzip/vee-validate@next)](https://bundlephobia.com/result?p=vee-validate@next)
  [![Average time to resolve an issue](http://isitmaintained.com/badge/resolution/logaretm/vee-validate.svg)](http://isitmaintained.com/project/logaretm/vee-validate 'Average time to resolve an issue')
  [![Percentage of issues still open](http://isitmaintained.com/badge/open/logaretm/vee-validate.svg)](http://isitmaintained.com/project/logaretm/vee-validate 'Percentage of issues still open')
  