Add primary command sample

- New spring-shell-sample-catalog which is a skeleton meant for
  future view overhaul work.
- Relates #755

spring-shell-samples/spring-shell-sample-catalog/src/main/resources/application.yml

@@ -0,0 +1,18 @@
+spring:
+  main:
+    banner-mode: off
+  shell:
+    noninteractive:
+      primary-command: catalog
+## disable console logging
+logging:
+  pattern:
+    console:
+## log debug from a cli
+#  file:
+#    name: shell.log
+#  level:
+#    root: debug
+#    org:
+#      springframework:
+#        shell: debug