README: Should Binary OR be Bitwise AND

In the README, should "binary OR" text in https://github.com/kitten/tiny-css-prefixer/blob/master/README.md?plain=1#L28-L29 be actually "bitwise AND" text https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_AND

So updated text is.
```
These are combined using a bitwise AND, so an example usage of the
`prefixProperty` helper may look like the following:
```