message: Update number of fns in README
diff: # It's like [Lodash](https://lodash.com) for dates
  -- It has [**180+ functions** for all occasions](https://date-fns.org/docs/).
  +- It has [**200+ functions** for all occasions](https://date-fns.org/docs/).
  - **Modular**: Pick what you need. Works with webpack, Browserify, or Rollup and also supports tree-shaking.
  - **Native dates**: Uses existing native type. It doesn't extend core objects for safety's sake.
  - **Immutable & Pure**: Built using pure functions and always returns a new date instance.
  