docs: update main readme (#96)

Author: ocofaigh

README.md

@@ -1,3 +1,8 @@
-# Core Security Services Stack
+# IBM Cloud Essential Security and Observability Services stack
 
-The Stack provisions Key Protect, Secrets Manager and Security and Compliance Center.
+[![Graduated (Supported)](https://img.shields.io/badge/status-Graduated%20(Supported)-brightgreen?style=plastic)](https://terraform-ibm-modules.github.io/documentation/#/badge-status)
+[![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
+[![pre-commit](https://img.shields.io/badge/pre--commit-enabled-brightgreen?logo=pre-commit&logoColor=white)](https://github.com/pre-commit/pre-commit)
+[![latest release](https://img.shields.io/github/v/release/terraform-ibm-modules/stack-ibm-core-security-services?logo=GitHub&sort=semver)](https://github.com/terraform-ibm-modules/stack-ibm-core-security-services/releases/latest)
+
+The stack provisions Key Protect, Secrets Manager, Security and Compliance Center, Event Notifications, and Observability services. [Learn more](https://cloud.ibm.com/docs/security-services?topic=security-services-overview).