add docker support

Dockerfile

@@ -0,0 +1,29 @@
+# STAGE 1: Build
+FROM mcr.microsoft.com/dotnet/sdk:9.0 AS build
+# Set the working directory in the container
+WORKDIR /app
+
+# Copy the .csproj file and restore any dependencies
+# Doing this separately allows Docker to cache this layer
+COPY *.csproj ./
+RUN dotnet restore
+
+# Copy the rest of the application files
+COPY . ./
+
+# Build the application and publish it for production
+RUN dotnet publish -c Release -o /app/publish
+
+# STAGE 2: Runtime
+# Use the ASP.NET runtime image (much smaller than the SDK)
+FROM mcr.microsoft.com/dotnet/aspnet:9.0 AS runtime
+WORKDIR /app
+
+# Copy the published files from the build stage
+COPY --from=build /app/publish .
+
+# Expose the port your app runs on (usually 8080 in .NET 8+)
+EXPOSE 8080
+
+# Set the entrypoint for the application
+ENTRYPOINT ["dotnet", "Catalog26.dll"]