add core-team topic (#41)

Author: ocofaigh

.github/settings.yml

@@ -25,4 +25,4 @@ repository:
   # description: ""
 
   # Use a comma-separated list of topics to set on the repo (ensure not to use any caps in the topic string).
-  topics: terraform, ibm-cloud, terraform-stack, ibm-cloud-stack
+  topics: terraform, ibm-cloud, terraform-stack, ibm-cloud-stack, core-team