docs: add instructions to README

README.md

@@ -2,18 +2,27 @@
 S-DOM is a plugin for IntelliJ IDEA that allows you to submit your code to the DOMjudge system directly from the IDE.
 It isn't a full replacement for the web interface yet, but already matches or surpasses the web UI in most tasks.
 
+You can download the plugin from the [JetBrains Marketplace](https://plugins.jetbrains.com/plugin/24446-s-dom-for-domjudge).
+
 ## Features
 - Simple, one-click submissions and feedback (no need for File Explorer or reloading!)
 - View problems and problem statements without leaving your IDE
 - Unobtrusive and integrated
 - Detects the language of submitted files
 
+<!-- Note to writers: A copy of the feature list exists in plugin.xml, please also add your changes there -->
+
 ## Potential future features
 - Display how much time is left in a contest or whether it's already over
 - Implement reading detailed results
 - Show scoreboards
 - Maybe even download test cases and scaffold sources
 
+## Contributing
+If you want to contribute, feel free to fork the [GitLab repository](https://gitlab.com/JFronny/s-dom) and submit a merge request there.
+I'm happy to accept any help, be it bug fixes, new features, or just code cleanup.
+Please note that I will merge MRs locally, so don't be surprised if your MR is marked as closed without merging.
+
 ## References
 - [DOMjudge](https://www.domjudge.org/documentation)
 - [DOMjudge API](https://domjudge.iti.kit.edu/main/api/doc)