doc for config file

rest-api/src/main/java/lcsb/mapviewer/api/ContentNegotiationConfig.java

@@ -5,6 +5,22 @@ import org.springframework.web.servlet.config.annotation.ContentNegotiationConfi
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 
+/**
+ * This class is a configuration for spring that disables content type
+ * recognition based on the "extension" (last part after dot in url). It allows
+ * API to return json for urls like: http://localhost:8080/minerva/api/users/t.t
+ * 
+ * More info can be found here:
+ * <ul>
+ * <li>https://spring.io/blog/2013/05/11/content-negotiation-using-spring-mvc
+ * </li>
+ * <li>https://stackoverflow.com/questions/30793717/spring-throwing-
+ * httpmediatypenotacceptableexception-could-not-find-acceptable-r</li>
+ * </ul>
+ * 
+ * @author Piotr Gawron
+ *
+ */
 @Configuration
 @EnableWebMvc
 public class ContentNegotiationConfig extends WebMvcConfigurerAdapter {