Documentation : Improve selective sync documentation
Geo currently supports selective sync by namespace and by shard. Some customers want to selectively sync projects to certain nodes, and a subset of those want to restrict the metadata.
For customers who aren't concerned about the metadata, what we have now meets their needs, but they don't know enough about the feature to be able to use it.
This issue is to improve the selective sync documentation to be more clear about what the feature is, and what is (and is not) covered by selective synchronization.