update gitignore and remove untracked files

.gitignore

@@ -1,33 +1,35 @@
-HELP.md
+### Java & Maven ###
 target/
-.mvn/wrapper/maven-wrapper.jar
-!**/src/main/**/target/
-!**/src/test/**/target/
+*.class
+*.war
+*.ear
+*.jar
+*.lst
 
-### STS ###
+### Logs ###
+logs/
+*.log
+
+### IntelliJ IDEA ###
+.idea/
+*.iml
+*.iws
+*.ipr
+out/
+
+### STS / Eclipse ###
 .apt_generated
 .classpath
 .factorypath
 .project
-.settings
+.settings/
 .springBeans
 .sts4-cache
 
-### IntelliJ IDEA ###
-.idea
-*.iws
-*.iml
-*.ipr
-
-### NetBeans ###
-/nbproject/private/
-/nbbuild/
-/dist/
-/nbdist/
-/.nb-gradle/
-build/
-!**/src/main/**/build/
-!**/src/test/**/build/
-
 ### VS Code ###
 .vscode/
+
+### OS files ###
+.DS_Store
+Thumbs.db
+desktop.ini

HELP.md

@@ -0,0 +1,31 @@
+# Getting Started
+
+### Reference Documentation
+For further reference, please consider the following sections:
+
+* [Official Apache Maven documentation](https://maven.apache.org/guides/index.html)
+* [Spring Boot Maven Plugin Reference Guide](https://docs.spring.io/spring-boot/4.1.0-SNAPSHOT/maven-plugin)
+* [Create an OCI image](https://docs.spring.io/spring-boot/4.1.0-SNAPSHOT/maven-plugin/build-image.html)
+* [Spring Boot DevTools](https://docs.spring.io/spring-boot/4.1.0-SNAPSHOT/reference/using/devtools.html)
+* [Spring Web](https://docs.spring.io/spring-boot/4.1.0-SNAPSHOT/reference/web/servlet.html)
+* [Spring Data JPA](https://docs.spring.io/spring-boot/4.1.0-SNAPSHOT/reference/data/sql.html#data.sql.jpa-and-spring-data)
+* [Spring Security](https://docs.spring.io/spring-boot/4.1.0-SNAPSHOT/reference/web/spring-security.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/rest/)
+* [Accessing Data with JPA](https://spring.io/guides/gs/accessing-data-jpa/)
+* [Securing a Web Application](https://spring.io/guides/gs/securing-web/)
+* [Spring Boot and OAuth2](https://spring.io/guides/tutorials/spring-boot-oauth2/)
+* [Authenticating a User with LDAP](https://spring.io/guides/gs/authenticating-ldap/)
+
+### Maven Parent overrides
+
+Due to Maven's design, elements are inherited from the parent POM to the project POM.
+While most of the inheritance is fine, it also inherits unwanted elements like `<license>` and `<developers>` from the parent.
+To prevent this, the project POM contains empty overrides for these elements.
+If you manually switch to a different parent and actually want the inheritance, you need to remove those overrides.
+