docs: document features in README file (#83)

Author: Djaytan

.github/workflows/ci.yml

@@ -16,6 +16,8 @@ permissions: {}
 # TODO: Experiment GitHub deployments
 # TODO: do we want to test multi-arch build?
 # TODO: reproductible builds? https://docs.docker.com/build/ci/github-actions/reproducible-builds/
+# TODO: SonarQube integration at both CI and Docker Scout levels?
+# TODO: Migrate from Trivy to Docker Scout
 jobs:
   build-and-test:
     name: Build & Test

README.md

@@ -11,32 +11,62 @@
 
 Dockerized and fine-grained customizable PaperMC server.
 
+Available in [Docker Hub](https://hub.docker.com/r/djaytan/papermc-server).
+
 </div>
 
-## Features
+## ✨ Features
+
+* **[Alpine](https://hub.docker.com/_/alpine)-based image**
+* **Lightweight**: ~360 MB
+* **Minimalist**: Includes only essential dependencies to reduce image size and surface area
+* **Rootless**: Runs as a non-root user by default
+* **Multi-architecture support**: Built for `amd64` & `arm64` (additional architectures available on request)
+* **JRE 21**, based on [Eclipse Temurin](https://hub.docker.com/_/eclipse-temurin)
+  * Custom-built using `jlink` to minimize size
+  * Includes all standard Java modules to ensure broad compatibility with plugins
+* Scanned by [Trivy](https://trivy.dev/latest/) and [Docker Scout](https://docs.docker.com/scout/) **to detect security vulnerabilities**
+
+### 🛠️ Planned Features
 
-* Alpine-based image
-* Lightweight (~360 MB)
-* Multi-architecture support (amd64 & arm64)
+The image is under active development, with the following enhancements planned:
 
-TODO
+* **Healthcheck integration**: Built-in Docker `HEALTHCHECK` instruction for better container observability.
+* **Unified configuration interface**: Centralized PaperMC tuning via a config file, with optional environment variable overrides (which will be the main difference with [itzg's solution](https://docker-minecraft-server.readthedocs.io/en/latest/configuration/interpolating/)).
+* **Customizable server startup options**: Ability to set JVM options and server properties via environment variables.
+* **Enable/Disable Aikar's flags**: Aikar's researches ([link](https://aikar.co/2018/07/02/tuning-the-jvm-g1gc-garbage-collector-flags-for-minecraft/)) and [PaperMC recommendations](https://docs.papermc.io/paper/aikars-flags/)
+* **Configurable TimeZone**
+* **UID/GID-agnostic:** Support for running the server with configurable UID/GID (typically required when running container in OpenShift).
+* **Auto-updating builds**: Scheduled rebuilds for including upstream JDK/PaperMC updates and security patches.
+* **Compliancy with [OWASP Docker rules](https://cheatsheetseries.owasp.org/cheatsheets/Docker_Security_Cheat_Sheet.html)**
+* **GraalVM variant**
 
-## Contributing
+The below features may be implemented too, but are not a priority:
+
+* **Configurable Java module set**: Option to build smaller JREs by selecting only required Java modules.
+* **Support JMX**: Java Management Extensions enabling for remote management and monitoring (e.g., with [VisualVM](https://visualvm.github.io/), [JMC](https://openjdk.org/projects/jmc/), ...) => [spark](https://docs.papermc.io/paper/profiling/) may be preferred.
+* **Documentation**: Comprehensive documentation for all features and configurations with [AsciiDoc](https://asciidoc.org/).
+* **Share examples**
+* **OpenJ9 variant**
+
+## 🌍 Contributing
 
 If you want to help us improve the project, you can learn more about ways to do so [here](docs/CONTRIBUTING.md).
 
-## Versioning
+Have a feature request? Don't hesitate to [fill an issue](https://github.com/Djaytan/docker-papermc-server/issues)!
+
+## 🏷️ Versioning
 
 This project follows [Semantic Versioning](https://semver.org/).
 
 The Docker tagging scheme is `<mc-version>-v<image-version>-<timestamp-YYYYMMDD>` (e.g. `1.21.4-v1.2.1-20250406`)
 
-## Security Policy
+## 🔒 Security Policy
 
 In case you think having found a security vulnerability, please consult
 our [Security Policy](docs/SECURITY.md).
 
-## Licence
+## 📄 Licence
 
 This project inherits its licensing from the included upstream projects. As such, it is licensed under
 the [GNU GPL v3.0](https://www.gnu.org/licenses/gpl-3.0.html) license, as it inherits from PaperMC, which in turn inherits it from the original Bukkit and

src/main/docker/Dockerfile

@@ -16,7 +16,6 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
-# TODO: migrate to Podman? https://cheatsheetseries.owasp.org/cheatsheets/Docker_Security_Cheat_Sheet.html#podman-as-an-alternative-to-docker
 FROM docker.io/eclipse-temurin:21-jdk-alpine@sha256:2f2f553ce09d25e2d2f0f521ab94cd73f70c9b21327a29149c23a2b63b8e29a0 AS jre-build
 
 # Create a custom Java runtime