Please see this recent thread on a very similar topic https://learn.microsoft.com/en-us/answers/questions/1188012/how-to-deploy-a-monitor-alerts-rule-with-our-solut
You can create a Sentinel Analytic do do the same (probably), and contribute using these instructions: https://github.com/Azure/Azure-Sentinel#contributing
There is a Azure Monitor community Github as well: https://github.com/microsoft/AzureMonitorCommunity
If this helps, please "accept" the answer. Best wishes