Document What Incremental Strategies Are Supported

[ernestoongaro]

Thanks to @Victoriapm for reporting that MERGE does not work in Fabric yet. We need to know which incremental strategies are supported on Fabric today.

The default seems to be delete+insert. Which ones are supported and which ones are not?

Definition of done:

1. We know which ones are supported
2. File Issues to give errors if trying one that isn't supported
3. Update the table with fabric supported ones
4. Update Fabric docs https://docs.getdbt.com/reference/resource-configs/fabric-configs

[prdpsvs]

@ernestoongaro , Let me do that. I may need a couple of weeks, but I will get to this.

[prdpsvs]

@ernestoongaro , Fabric currently support insert+delete. If unique key is not provided, it will default to append mode. I will update this in the documentation.

[ernestoongaro]

closed in dbt-labs/docs.getdbt.com#5614 and dbt-labs/docs.getdbt.com#5613