### decapitalize

Decapitalizes the first letter of a string.

Use array destructuring and `String.toLowerCase()` to decapitalize first letter, `...rest` to get array of characters after first letter and then `Array.join('')` to make it a string again.
Omit the `upperRest` parameter to keep the rest of the string intact, or set it to `true` to convert to uppercase.

```js
const decapitalize = ([first, ...rest], upperRest = false) =>
  first.toLowerCase() + (upperRest ? rest.join('').toUpperCase() : rest.join(''));
```

```js
decapitalize('FooBar'); // 'fooBar'
decapitalize('FooBar', true); // 'fOOBAR'
```