Fix links bug in documentation

backend/README.md

@@ -43,19 +43,19 @@ Inside this directory, you can find the code for the database and the REST API.
 For further reference, please consider the following sections:
 
 * [Official Gradle documentation](https:\\docs.gradle.org)
-* [Spring Boot Gradle Plugin Reference Guide](https:\\docs.spring.io\spring-boot\docs\2.4.1\gradle-plugin\reference\html\)
+* [Spring Boot Gradle Plugin Reference Guide](https:\\docs.spring.io\spring-boot\docs\2.4.1\gradle-plugin\reference\html)
 * [Create an OCI image](https:\\docs.spring.io\spring-boot\docs\2.4.1\gradle-plugin\reference\html\#build-image)
 * [Spring Web](https:\\docs.spring.io\spring-boot\docs\2.4.1\reference\htmlsingle\#boot-features-developing-web-applications)
-* [Spring Data JDBC](https:\\docs.spring.io\spring-data\jdbc\docs\current\reference\html\)
+* [Spring Data JDBC](https:\\docs.spring.io\spring-data\jdbc\docs\current\reference\html)
 
 ### Guides
 The following guides illustrate how to use some features concretely:
 
-* [Building a RESTful Web Service](https:\\spring.io\guides\gs\rest-service\)
-* [Serving Web Content with Spring MVC](https:\\spring.io\guides\gs\serving-web-content\)
-* [Building REST services with Spring](https:\\spring.io\guides\tutorials\bookmarks\)
+* [Building a RESTful Web Service](https:\\spring.io\guides\gs\rest-service)
+* [Serving Web Content with Spring MVC](https:\\spring.io\guides\gs\serving-web-content)
+* [Building REST services with Spring](https:\\spring.io\guides\tutorials\bookmarks)
 * [Using Spring Data JDBC](https:\\github.com\spring-projects\spring-data-examples\tree\master\jdbc\basics)
-* [Accessing data with MySQL](https:\\spring.io\guides\gs\accessing-data-mysql\)
+* [Accessing data with MySQL](https:\\spring.io\guides\gs\accessing-data-mysql)
 
 ### Additional Links
 These additional references should also help you: