[migration] Provide migration guide/codemods for migrating from v4 to v6

[mnajdova]

Summary

This issue is created in order to get traction of the need for providing a migration guide and/or codemods for upgrading from v4 to v6 directly. Currently around one-quarter of the downloads come from v4, however it is not clear how big a percentage of these downloads comes from projects that are never going to be migrated, planned to be migrated, or are currently being migrated v5.

I would ask anyone who is on v4 and who is looking into migrating to v6 to upvote the issue, based on the interest we may spend some time to help and provide clearer guidance or codemods to make this easier.

Motivation

The v4 to v5 migration was reported as a very hard upgrade. If we can avoid having people to migrate to v5, just so that they can get v6, it would be great.

Search keywords: migration, v4, v6