Improve layer caching in Docker build

Dockerfile

@@ -1,17 +1,32 @@
 FROM mcr.microsoft.com/dotnet/sdk:7.0-alpine AS build
 WORKDIR /src
-COPY . ./
-WORKDIR Groceries
+
+COPY ./.config ./
+RUN dotnet tool restore
+
+COPY ./Groceries.sln ./
+COPY */*.csproj ./
+RUN for file in $(ls *.csproj); do mkdir -p ${file%.*} && mv $file ${file%.*}; done
 RUN dotnet restore
+
+COPY ./Groceries/libman.json ./
+WORKDIR Groceries
+RUN dotnet libman restore
+
+COPY . ../
 RUN dotnet publish --no-restore --output /out
 
 FROM mcr.microsoft.com/dotnet/aspnet:7.0-alpine AS base
 WORKDIR /groceries
+
 COPY --from=build /out .
 COPY --from=build /src/Groceries/config.ini /config/
+
 RUN apk add --no-cache icu-libs tzdata
+
 ENV DOTNET_ENABLEDIAGNOSTICS=0
 ENV DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=false
+
 EXPOSE 80
 VOLUME /config
 ENTRYPOINT ["./Groceries", "--data", "/config"]