Inserting JavaDoc for credential ID search

src/main/java/CredentialRepository.java

@@ -62,6 +62,12 @@ public class CredentialRepository implements CredentialRepositoryInterface{
     }
 
 
+    /**
+     * Function to return a specific Credential via ID
+     * @param id
+     * @return usercredential | NULL
+     */
+
     @Override
     public Credential getCredentialsViaId(int id) {