Update README

Author: ihiverlet

README.md

@@ -500,7 +500,7 @@ You can use a configuration with a master local for example.
     "type": "object",
     "description": "spark specific configuration",
     "properties": {
-        "sparkui": {
+        "ui": {
             "type": "boolean",
             "title": "SparkUI",
             "description": "Enable Spark monitoring interface",
@@ -509,6 +509,15 @@ You can use a configuration with a master local for example.
                 "hidden": true
             }
         },
+        "hostname": {
+            "type": "string",
+            "title": "Hostname",
+            "pattern": "^([a-zA-Z0-9-]+\.)*mydomain\.com$",
+            "x-onyxia": {
+                "hidden": true,
+                "overwriteDefaultWith": "{{project.id}}-{{k8s.randomSubdomain}}-0.mydomain.com"
+            }
+        },
         "disabledCertChecking": {
             "title": "Disable certificate checking ",
             "type": "boolean",