[docs] Add instructions to fork repo to IDE setup page (#599)

Author: michaelkoepf

website/community/dev/ide-setup.md

@@ -34,14 +34,24 @@ that has a bug or is not properly set up.
 Using the included [Maven Wrapper](https://maven.apache.org/wrapper/) by replacing `mvn` with `./mvnw` ensures that the correct Maven version is used.
 :::
 
-## Preparation
+## Preparation: Fork and Clone the Fluss Repository
 
-To get started, please first checkout the Fluss sources from our
-[repository](https://github.com/alibaba/fluss),
-e.g.
+Fluss uses [git](http://git-scm.com/) for version control.
+The Git repository is mirrored to [GitHub](https://github.com/alibaba/fluss/).
+
+The common way to merge code changes on GitHub is to fork the repository (creating a copy of the repository to your personal GitHub account so you can modify the source code) and issue a pull request.
+
+1. To fork the Fluss repository, log in with your GitHub account. If you do not have one yet, [sign up for free](https://github.com/signup). Then, click the `[Fork]` button on the upper right of the [Fluss repository](https://github.com/alibaba/fluss/).
+2. Clone the _forked_ version of the repository over HTTPs or SSH. SSH is recommended but needs to be [explicitly configured](https://docs.github.com/en/authentication/connecting-to-github-with-ssh).
+
+```bash
+# Clone using HTTPs
+git clone https://github.com/<your-user-name>/fluss.git
+```
 
 ```bash
-git clone [email protected]:alibaba/fluss.git
+# Clone using SSH
+git clone [email protected]:<your-user-name>/fluss.git
 ```
 
 ## IntelliJ IDEA