Add Crowdsec and Caddy bouncer to gateway

gateway/caddy/Dockerfile

@@ -0,0 +1,15 @@
+ARG CADDY_VERSION=2
+
+FROM caddy:${CADDY_VERSION}-builder-alpine AS builder
+
+RUN xcaddy build \
+    --with github.com/mholt/caddy-l4 \
+    --with github.com/caddyserver/transform-encoder \
+    --with github.com/hslatman/caddy-crowdsec-bouncer/http@main \
+    --with github.com/hslatman/caddy-crowdsec-bouncer/layer4@main
+
+FROM caddy:${CADDY_VERSION} AS caddy
+
+WORKDIR /
+
+COPY --from=builder /usr/bin/caddy /usr/bin/caddy