V2 data file content is not human readable when written in non latin alphabeth

One of the advantages people see in flat file CMS is that data is human readable.
This is true for Automad except when text is not in English
I would suggest to add this flag to JSON encoding:
`JSON_UNESCAPED_UNICODE`
https://github.com/marcantondahmen/automad/blob/12998c1b0fa7a35c99ad45565f36154b55b839fd/automad/src/server/Core/FileSystem.php#L628C75-L628C97