`journal_name` option does not exist

[thatsmydoing]

The README states that the journal index name can be customized with journal_name https://github.com/toptal/chewy/?tab=readme-ov-file#journaling but that logic seems to have been removed since the journal was moved into chewy_specifications as part of #540

Since then, the journal was split back into its own index but the name is fixed at chewy_journal. The stale documentation seems to suggest this can be customized but that doesn't seem to be the case.

Expected behavior

Chewy uses journal_name as the journal index name.

Actual behavior

Chewy always uses chewy_journal. Or remove mention of journal_name from the docs.

Steps to reproduce the problem

Set journal_name in the chewy configuration.

Version Information

Share here essential version information such as:

• Chewy version: 7.6.0
• Elasticsearch version: 7.17
• Ruby version: 3.4.1
• Rails version: 7.1.5.1