Updates proxy cache API calls (quay#1503)

Co-authored-by: Steven Smith <[email protected]>

Author: stevsmit

modules/api-organization-createProxyCacheConfig.adoc

@@ -57,5 +57,7 @@ $ curl -X POST "https://<quay-server.example.com>/api/v1/organization/<orgname>/
   -H "Content-Type: application/json" \
   -d '{
         "upstream_registry": "<upstream_registry>"
+        "upstream_registry_username": "your_robot_account_username"
+        "upstream_registry_password": "your_robot_account_password"
       }'
 ----

modules/api-organization-validateProxyCacheConfig.adoc

@@ -56,6 +56,7 @@ $ curl -X POST "https://<quay-server.example.com>/api/v1/organization/{orgname}/
   -H "Content-Type: application/json" \
   -d '{
         "upstream_registry": "<upstream_registry>"
+        "upstream_registry_username": "your_robot_account_username"
+        "upstream_registry_password": "your_robot_account_password"
       }'
-
 ----

modules/org-proxy-cache-configuration-api.adoc

@@ -19,6 +19,8 @@ $ curl -X POST "https://<quay-server.example.com>/api/v1/organization/<orgname>/
   -H "Content-Type: application/json" \
   -d '{
         "upstream_registry": "<upstream_registry>"
+        "upstream_registry_username": "your_robot_account_username"
+        "upstream_registry_password": "your_robot_account_password"
       }'
 ----
 
@@ -31,6 +33,8 @@ $ curl -X POST "https://<quay-server.example.com>/api/v1/organization/{orgname}/
   -H "Content-Type: application/json" \
   -d '{
         "upstream_registry": "<upstream_registry>"
+        "upstream_registry_username": "your_robot_account_username"
+        "upstream_registry_password": "your_robot_account_password"
       }'
 ----