Update docker build to fix permissions

dockerfile

@@ -7,6 +7,14 @@ RUN mkdocs build -d $SITE_DIR
 
 
 FROM caddy:alpine
+USER root
+RUN apk add --no-cache libcap && \
+    setcap -r /usr/bin/caddy && \
+    chmod +x /usr/bin/caddy
+
+
 COPY --from=builder /app/site /srv
+
+USER 1000
 EXPOSE 8080
-CMD ["caddy", "file-server", "--listen", ":8080"]
+CMD ["caddy", "file-server", "--listen", ":8080"]