Changed entity_api_url in example config and added

more descriptive text

src/instance/app.cfg.example

@@ -32,8 +32,10 @@ INGEST_API_URL = 'https://ingest-api.dev.hubmapconsortium.org'
 # Works regardless of the trailing slash
 ONTOLOGY_API_URL = 'https://ontology-api.dev.hubmapconsortium.org'
 
-# URL for talking to Entity API (default for DEV)
-ENTITY_API_URL = 'https://entity-api.dev.hubmapconsortium.org'
+# URL for talking to Entity API (default for Localhost)
+# This is the same URL base where entity-api is running. This is useful in places where a call for one entity
+# necessitates subsequent calls for other entities.
+ENTITY_API_URL = 'http://localhost:5002'
 
 # A list of URLs for talking to multiple Search API instances (default value used for docker deployment, no token needed)
 # Works regardless of the trailing slash /