[Unity Catalog] Modify ReadMe to reflect the pre-requisite of having a Regional Metastore

[thesqlpro]

Task for For #765
Top Priority - simple documentation that explains creation of the Metastore in a region along with Unity Catalog. Automation is a nice to have task (#985).

Initially this was the route we were going (automation) but there are a lot of complexities in creating a Unity Catalog metastore. APIs and CLI are limited and much of it is not documented as well on Azure as it in in AWS. The team made the decision to use the Readme to make this a prerequisite to using the repo.

DoD

• Simplified documentation added to pre-requisites in the readme.md to show creation process of Unity Catalog
• Instructions to create sensordata catalog
• Instructions added to deploy_infrastructure.sh (notifying the user to check for/create sensordata catalog)

[ydaponte]

@thesqlpro, please do add a DoD and fill in the metadata.