Update Caddy, enable logging, & validate Caddyfile on build

Author: pimterry

Caddyfile

@@ -1,4 +1,6 @@
 {$DOMAIN:http://localhost} {
+    log
+
     encode zstd gzip
 
     header *.wasm Content-Type "application/wasm"

Dockerfile

@@ -1,8 +1,10 @@
-FROM caddy:2.6.1-alpine
+FROM caddy:2.9.1-alpine
 
 RUN mkdir /site
 
 WORKDIR /site
 
 COPY ./dist /site
-COPY ./Caddyfile /etc/caddy/Caddyfile
+
+COPY ./Caddyfile /etc/caddy/Caddyfile
+RUN caddy validate --config /etc/caddy/Caddyfile