document additional bootstrap issues

**Describe the content issue**:
A clear and concise description of what the content issue is. Is there content missing or is there incorrect content?

document additional bootstrapping troubleshooting: https://github.com/aws-amplify/docs/issues/7482
Such as checking the CDKToolKit stack events for failures
Mitigation steps if the stack failed on asset bucket when recreating the toolkit stack.

**URL page where content issue is**:
https://docs.amplify.aws/react/build-a-backend/troubleshooting/stack-cdktoolkit-already-exists/