[DSC-2038] Add setting note

Author: atarix83

config/config.example.yml

@@ -187,6 +187,8 @@ submission:
     metadataDetailsList:
       - label: 'Document type'
         name: dc.type
+  # Minimum number of characters required before performing a lookup.
+  minChars: 3
 
 #  Default Language in which the UI will be rendered if the user's browser language is not an active language
 defaultLanguage: en

src/config/default-app-config.ts

@@ -294,6 +294,7 @@ export class DefaultAppConfig implements AppConfig {
       // NOTE: list of metadata fields for which the dropdown hint is enabled
       // eg. 'dc.access.rights': true,
     },
+    // Minimum number of characters required before performing a lookup.
     minChars: 3,
   };