Does this respect the user's locale for number formatting?

Question

RepoPilot · Accepted Answer

Yes, pretty-bytes respects the user's locale for number formatting through the `locale` option.

The library provides a `toLocaleString` function [index.js:L55-L65] that handles locale-aware formatting. It supports three modes:

1. **String locale**: Pass a specific BCP 47 language tag like `'de'` or `'en'`
2. **System locale**: Pass `locale: true` to use the browser/system default
3. **Locale array**: Pass multiple locale options as a fallback chain, e.g., `['unknown', 'de', 'en']`

When a locale is provided, the function calls JavaScript's native `Number.toLocaleString()` with the specified locale, which handles decimal separators and thousands separators according to that locale's conventions.

For example [test.js:L75-L76]:
```js
t.is(prettyBytes(1001, {locale: 'de'}), '1 kB');  // German uses space for thousands
t.is(prettyBytes(1001, {locale: 'en'}), '1 kB');  // English uses comma
```

And for larger numbers [test.js:L79-L80]:
```js
t.is(prettyBytes(1e30, {locale: 'de'}), '1.000.000 YB');  // German: dots as thousands separator
t.is(prettyBytes(1e30, {locale: 'en'}), '1,000,000 YB');  // English: commas
```

If no locale is specified or `locale: false`, the number formatting is not localized [index.js:L55-L65].

FOLLOW_UPS:
- How does the library handle fraction digits with locale?
- What happens when you pass an invalid locale string?
- Does binary mode support locale formatting?