Highlighter breaks when searching for special characters

[mshibl]

First, thank you for building this neat react component.

I've found a bug where passing any special character breaks the internal regex matching in Highlighter Component.

Here's a demo demonstrating the bug:
https://codesandbox.io/s/204r9kz6lj

[ViktorSoroka07]

This is rather a bug of react-highlight-words and not of the react-highlighter current one.