Sort of get config to work

config/packages/pcm_icon.yaml

@@ -0,0 +1,19 @@
+when@dev:
+    pcm_icon:
+        directories:
+            - '%kernel.project_dir%/public/icons'
+        palletes: []
+
+when@prod:
+    pcm_icon:
+        directories:
+            - '%kernel.project_dir%/public/icons'
+        palletes: []
+
+when@test:
+    pcm_icon:
+        directories:
+            - '%kernel.project_dir%/tests/icons'
+        palletes:
+            - []
+