Add search exposed config endpoint

Author: J4bbi

configuration.md

@@ -3,14 +3,15 @@
 ## Main Endpoint
 **/api/config/properties**   
 
-As we don't have yet an use case to iterate over all the configuration properties the main endpoint is not implemented and a 405 error code is returned according to our [general error response codes](README.md#Error codes).
+As we don't have yet an use case to iterate over all the configuration properties the main endpoint is not implemented and a 405 error code is returned according to our [general error response codes](README.md#Error-Codes).
 
 ## Single property
 **/api/config/properties/<:property>**
 
 This endpoint provides functionality to retrieve certain (configurable) configuration properties. 
 The DSpace server will have a whitelist of properties that can be retrieved by this endpoint.
 
+For example:
 
 ```json
 {
@@ -21,5 +22,40 @@ The DSpace server will have a whitelist of properties that can be retrieved by t
 }
 ```          
 
-* 200 OK - if the operation succeed
-* 404 Not found - if the property doesn't exist or isn't configured to be retrieved
+* 200 OK - if the operation succeeded
+* 404 Not found - if the property doesn't exist or isn't configured to be exposed
+
+## Search methods
+### top
+**/api/config/properties/search/exposed**
+
+The supported parameters are:
+* page, size [see pagination](README.md#Pagination)
+
+This endpoint returns all exposed configuration variables.
+
+For example:
+
+```json
+[{
+  "name": "google.analytics.key",
+  "values": [ 
+      "UA-XXXXXX-X"
+   ]
+},
+{
+  "name": "websvc.opensearch.autolink",
+  "values": [ 
+      true
+   ]
+},
+{
+  "name": "orcid.authorize-url",
+  "values": [ 
+      "https://sandbox.orcid.org/oauth/authorize"
+   ]
+}]
+```
+
+* 200 OK - if the operation succeeded
+* 404 Not found - if no property is configured to be exposed