add CODEOWNER and service.yml

.github/CODEOWNERS

@@ -0,0 +1 @@
+*       @shopify/app-partner-dev-tools-education

service.yml

@@ -0,0 +1,8 @@
+audience: partner
+classification: library
+org_line: App & Partner Platform
+owners:
+  - Shopify/app-partner-dev-tools-education
+slack_channels:
+  - dev-tools-education
+  - api-patterns-team