Add GitHub Action for Docker server build

.github/workflows/docker-server.yml

@@ -0,0 +1,24 @@
+name: Build and Push Docker Server Image
+
+on:
+  push:
+    paths:
+      - 'src/RemoteExec.Server/**'
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    name: Build & Push Server Image
+    steps:
+      - uses: actions/checkout@v4
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Build the Docker image
+        run: docker build -t ${{ secrets.DOCKERHUB_USERNAME }}/remoteexec-server:latest ./src/RemoteExec.Server
+      - name: Push the Docker image
+        run: docker push ${{ secrets.DOCKERHUB_USERNAME }}/remoteexec-server:latest