docs: add a join-the-Discord badge and community section to the README (#104)

README.md

@@ -7,6 +7,8 @@
 
 DroidDeck brings the SteamOS experience to Android: Valve's Steam client in Big Picture on your Adreno handheld, with Windows games through Valve's ARM64 Proton.
 
+<p align="center"><a href="https://discord.gg/JRGAvawjsm"><img src="https://img.shields.io/badge/Discord-Join%20the%20community-5865F2?logo=discord&logoColor=white" alt="Join the DroidDeck Discord"></a></p>
+
 <p align="center"><img src="docs/releases/media/0.2.0/launch-into-steam.gif" width="80%" alt="Tapping DroidDeck on the Android home screen and landing in Steam Big Picture"></p>
 
 ## Requirements and install
@@ -15,6 +17,10 @@ Use Android 9 or newer on a supported Adreno device (730 or newer, or 8xx). Mali
 
 On Android 12+, if Steam exits without a log, turn off **Restrict child processes** in Developer options.
 
+## Community
+
+Join the [DroidDeck Discord](https://discord.gg/JRGAvawjsm) for help, nightly builds, and device reports. Bug reports go in its **#bug-reports** forum; attach the session folder from `Download/DroidDeck/` so the logs come with it.
+
 ## Build
 
 Run `tools/build_local.sh` with Docker, Java 17, the Android SDK/NDK, and `zstd` installed. It builds the ARM64 audio sinks from PulseAudio 13.0 and packages them into the APK at `app/build/outputs/apk/release/app-release.apk`. Set `DROIDDECK_PA13_SOURCE_DIR` to an existing PulseAudio 13.0 source directory to skip downloading it. To install the APK on an attached device, run `tools/deploy_local.sh`.