Add Docker deployment config and v3.02 firmware docs

Deployment: Dockerfile (multi-stage dev/prod with Caddy static
serving), docker-compose.yml (caddy-docker-proxy labels),
Caddyfile, Makefile, .dockerignore.

Docs: v3.02 firmware page, v3.01 updates.

site/Caddyfile

@@ -0,0 +1,11 @@
+:80 {
+	root * /srv
+	encode gzip
+
+	handle /health {
+		respond "ok" 200
+	}
+
+	try_files {path} {path}/index.html {path}/ /index.html
+	file_server
+}