User Guide: add Oracle JDK Windows installer link

The User Guide currently points users to the direct OpenJDK download page, but it does not provide a convenient installer option. An installer is much more user friendly since some people may not know what to do with the JDK after they download it. They might not know they need to add java to the path in order to

Could the Java links under **System Requirements** be changed from:

```markdown
* Download - [https://jdk.java.net/](https://jdk.java.net/)
* Source Code - [https://github.com/openjdk/jdk/](https://github.com/openjdk/jdk/)
```
to:
```markdown
* Windows Installer - [Oracle JDK 26 Downloads](https://www.oracle.com/java/technologies/downloads/#jdk26-windows) (select the x64 Installer)
* Direct Download - [https://jdk.java.net/](https://jdk.java.net/)
* Source Code - [https://github.com/openjdk/jdk/](https://github.com/openjdk/jdk/)
```

This keeps the existing direct-download option while providing a more convenient installer for users who are less tech savy.