Add Dockerfile and gitea workflow

Dockerfile

@@ -0,0 +1,25 @@
+FROM alpine:3.22.1 as zine
+ARG ZINE_VERSION=v0.11.1
+
+ARG TARGETARCH
+RUN apk add --no-cache curl tar xz \
+  && case "$TARGETARCH" in \
+  amd64)  Z_ARCH="x86_64-linux-musl";; \
+  arm64)  Z_ARCH="aarch64-linux-musl";; \
+  *) echo "Unsupported TARGETARCH: $TARGETARCH" && exit 1;; \
+  esac \
+  && curl -L "https://github.com/kristoff-it/zine/releases/download/${ZINE_VERSION}/${Z_ARCH}.tar.xz" -o /tmp/zine.tar.xz \
+  && tar -C /usr/local/bin -xJf /tmp/zine.tar.xz zine \
+  && chmod +x /usr/local/bin/zine \
+  && zine --version
+
+FROM alpine:3.22.1 as builder
+COPY --from=zine /usr/local/bin/zine /usr/local/bin/zine
+WORKDIR /site
+COPY . .
+RUN zine release
+
+FROM nginx:alpine3.22 AS runner
+COPY --from=builder /site/public/ /usr/share/nginx/html/
+EXPOSE 80
+CMD ["nginx", "-g", "daemon off;"]