Added javadocs

Signed-off-by: Marcin Woźniak <y0rune@aol.com>

restservice/src/main/java/com/plannaplan/controllers/ConfigController.java

@@ -82,7 +82,9 @@ public class ConfigController {
         }
     }
 
-    public ResponseEntity<String> initAdmin(@RequestParam("ticket") String ticket){
+    @PostMapping(path = "/admin/init")
+    @ApiOperation("It can be run only in the initialization of the application. It will create admin user to manage the application.")
+    public ResponseEntity<String> initAdmin(@RequestParam("ticket") @ApiParam(value = "Ticket for validation.") String ticket){
         if (this.userService.adminExists()){
             return new ResponseEntity<>("Admin had been already created.", HttpStatus.FORBIDDEN);
         }