Adding Docker container build

Author: DarkWanderer

.github/workflows/container.yml

@@ -0,0 +1,38 @@
+name: Build Docker container
+
+on: [ workflow_dispatch ]
+
+jobs:
+  build_container:
+    name: Build container
+    runs-on: ubuntu-18.04
+    steps:
+      - uses: actions/checkout@v2
+
+      - id: string
+        uses: ASzc/change-string-case-action@v2
+        with:
+          string: ${{ github.repository_owner }}
+
+      - name: Build x64 binary
+        run: mkdir build && cd build && cmake .. && cmake --build . --parallel 2 --target sqfvm
+        env:
+          CC: clang
+          CXX: clang++
+
+      - name: Move binary to docker directory
+        run: mv build/sqfvm docker/
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build & push
+        uses: docker/build-push-action@v2
+        with:
+          context: docker
+          push: true
+          tags: ghcr.io/${{ steps.string.outputs.lowercase }}/sqfvm:latest

docker/Dockerfile

@@ -0,0 +1,5 @@
+FROM ubuntu:18.04
+LABEL org.opencontainers.image.source=https://github.com/SQFvm/runtime
+WORKDIR /tmp
+COPY sqfvm /usr/bin/sqfvm
+ENTRYPOINT /usr/bin/sqfvm