[DOCS]: Migration guide for upgrading to v1 beta

### Enhancement hasn't been filed before.

- [x] I have verified this enhancement I'm about to request hasn't been suggested before.

### Describe the enhancement you want to request

To help improve the v1 beta before its GA I think it would be extremely helpful to have a migration guide ready with the launch of the v1 beta to make it easier for more teams to test the beta out without running into undocumented roadblocks. This would increase the amount of eyes on the v1 beta to increase feedback gathered to have an even smoother v1 GA launch

Start by reviewing the v1 beta changes and identifying upgrade differences that could create undocumented roadblocks for existing teams. Done means a migration guide is available for the v1 beta launch and covers the relevant upgrade path before v1 GA.

Written by the indexing model from the issue text.