github workflows for build

.github/workflows/build.yml

@@ -0,0 +1,42 @@
+name: build
+
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+  schedule:
+    - cron: '0 6 * * 1' # weekly (every monday at 6 am UTC)
+
+jobs:
+  build:
+    runs-on: windows-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+
+      - name: setup DepotDownloader
+        shell: bash
+        run: |
+          mkdir depotdownloader
+          cd depotdownloader
+          curl -L 'https://github.com/SteamRE/DepotDownloader/releases/download/DepotDownloader_2.5.0/depotdownloader-2.5.0.zip' > depotdownloader.zip
+          unzip depotdownloader.zip
+
+      - name: setup Space Engineers
+        shell: bash
+        run: |
+          echo 'regex:^DedicatedServer64/' > filelist.txt
+          # https://steamdb.info/app/298740/depots/
+          depotdownloader/DepotDownloader.exe -app 298740 -depot 298741 -filelist filelist.txt -dir .
+          mv DedicatedServer64 .GameBinaries
+
+      - name: setup dotnet
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: 8.0.x
+
+      - name: build
+        run: dotnet build --configuration Release