docs: exoscale terraform v0.48

[robinAwallace]

What this PR does / why we need it:

The migration script for the new exoscale terraform. There are still som issues that needs to be addressed in exoscales terrafrom module. I just added it to the next release, but it may change before this is done.

Which issue this PR fixes: fixes #270

Public facing documentation PR (if applicable)

Special notes for reviewer:

Checklist:

• [ ] Proper commit message prefix on all commits
• [ ] Updated the public facing documentation
• Is this changeset backwards compatible for existing clusters? Applying:
  • [ ] is completely transparent, will not impact the workload in any way.
  • [ ] requires running a migration script.
  • [ ] requires draining and/or replacing nodes.
  • [ ] will break the cluster. I.e. full cluster migration is required.