Updated spacing and opacity to follow #18

[Faisal-Manzer]

This is a great package but I think this should directly match to tailwind's default. Let it be the choice of the user if they what to extend it beyond. There are only certain spacing available in default tailwind's conf.

A Thing I wanted to include in PR, but I didn't. I want your comment on this

This can be simplified

   maxHeight: theme => ({
      '0': '0',
      ...theme('spacing'),
      '1/2': '50%',
      '1/3': '33.333333%',
      '2/3': '66.666667%',
      '1/4': '25%',
      ....

To

   width: theme => ({
      '0': '0',
      ...theme.heigth(theme),
      screen: '100vw'
     })

This not only for width, but it is also for minHeight, maxHeight, maxWidth, minWidth. With some little changes. i.e. removing auto for others (except width).