updated docker file to help with caching

Dockerfile

@@ -5,7 +5,17 @@
 # on TARGETPLATFORM, so multi-arch (amd64 + arm64) runtime images are preserved.
 FROM --platform=$BUILDPLATFORM ghcr.io/hugomods/hugo:0.157.0 AS build
 WORKDIR /tmp/hugo
-COPY . .
+
+COPY go.mod ./
+RUN hugo mod get
+
+COPY archetypes ./archetypes
+COPY assets ./assets
+COPY content ./content
+COPY static ./static
+COPY themes ./themes
+COPY hugo.* ./
+
 RUN hugo --gc --minify
 
 FROM ghcr.io/static-web-server/static-web-server:2