Initial commit: Docusaurus docker stack and docs

site/Dockerfile

@@ -0,0 +1,15 @@
+FROM node:20-alpine
+
+WORKDIR /app
+
+# Installed as its own layer so it's only re-run when package.json actually changes.
+COPY package.json ./
+RUN npm install --no-audit --no-fund
+
+# Copy the rest of the scaffolded Docusaurus project (config, src/, static/).
+# The docs/ folder copied here is only a placeholder — docker-compose.yaml
+# bind-mounts the real markdown content from ../docs over the top of it at
+# container start, so editing docs never requires rebuilding this image.
+COPY . .
+
+EXPOSE 3000