Alphabetical sorting doesn't work for non-ASCII languages. Missing locale setting.

**Describe the bug**
Alphabetical sorting doesn't work for languages with special characters or according to locale. Non-ASCII characters will sort at the end of the list.

**To Reproduce**
Steps to reproduce the behavior:
1. Add a user with name starting with non-ASCII character, e.g. `Č`
2. Set `contributorsSortAlphabetically` to `true`
3. Open README.md
4. See user starting with `Č` at the end of the list instead in correct alphabetical order (which is for my locale after `C`)

**Expected behavior**
Users will be sorted correctly using specified locale.