Add 3rd party rulesets

Dockerfile

@@ -23,6 +23,28 @@ RUN OSU_VERSION=$(curl -s https://api.github.com/repos/ppy/osu/releases/latest |
         -p:Version=${OSU_VERSION} \
         osu.Desktop
 
+RUN for ruleset in \
+        "Bosu|https://github.com/EVAST9919/bosu" \
+        "Hitokori|https://github.com/Flutterish/Hitokori" \
+        "Karaoke|https://github.com/karaoke-dev/karaoke" \
+        "Mvis|https://github.com/EVAST9919/lazer-m-vis" \
+        "Rush|https://github.com/swoolcock/rush" \
+        "Sentakki|https://github.com/LumpBloom7/sentakki" \
+        "Swing|https://github.com/EVAST9919/lazer-swing" \
+        "Tau|https://github.com/Altenhh/tau" \
+    ; do \
+        repo_url="$(echo $ruleset | cut -d'|' -f2)" \
+        && assembly_name="osu.Game.Rulesets.$(echo $ruleset | cut -d'|' -f1)" \
+        && git clone --depth=1 "$repo_url" ruleset \
+        && cd ruleset \
+        && dotnet build \
+            -c Release \
+            "$assembly_name" \
+        && cp "${assembly_name}"/bin/Release/net*/"${assembly_name}".dll /opt/osu/ \
+        && cd .. \
+        && rm -rf ruleset \
+    ; done
+
 FROM mcr.microsoft.com/dotnet/core/runtime
 
 RUN apt-get update \