Add release workflow

This workflow will build the plugin and add the artifacts to newly created releases

.github/workflows/release.yml

@@ -0,0 +1,51 @@
+# This workflow will run every time a new release is created.
+# It will first build the plugin using Maven, then publish it to GitHub packages and finally attach the artifacts to the release
+
+name: Maven Package
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK 1.8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 1.8
+        server-id: github
+        settings-path: ${{ github.workspace }} # location for the settings.xml file
+
+    - name: Setup workspace
+      run: mkdir artifacts
+
+    - name: Build with Maven
+      run: |
+        mvn -B install package --file pom.xml -P ExcludeBadRabbit
+        cp Minepacks/target/M*.jar artifacts/
+
+    - name: Publish to GitHub Packages Apache Maven
+      run: 'mvn deploy -s $GITHUB_WORKSPACE/settings.xml "-DaltDeploymentRepository=github::default::https://maven.pkg.github.com/GeorgH93/Minepacks"'
+      env:
+        GITHUB_TOKEN: ${{ github.token }}
+
+    - name: Build with Maven (Standalone)
+      run: |
+        mvn -B clean install package --file pom.xml -P Standalone,ExcludeBadRabbit
+        mv Minepacks/target/M*.jar artifacts/
+
+    - name: Build with Maven (Release)
+      run: |
+        mvn -B package --file pom.xml -P Release
+        mv Minepacks/target/M*.jar artifacts/
+
+    - name: Upload the artifacts
+      uses: skx/github-action-publish-binaries@master
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        args: 'artifacts/M*'