Change Description

1. Setting a cost budget cap of $100 at the subscription level.
2. Email alerts will be triggered when 50%, 75%, and 90% thresholds are exceeded.
3. Email alerts will be routed to folks in subscription owner, and contributor roles.

Linked GitHub Issue

Fixes #110

Checklist

Please check all options that are relevant.

• I have made all necessary updates to the documentation.
• I have made all necessary updates to the provisioning scripts (bicep templates, github workflows).
• This is not a breaking change.