refactor: flatten shell/ dir and add ask screenshot to README

ask/Dockerfile

@@ -0,0 +1,37 @@
+FROM debian:12-slim
+
+RUN apt-get update -qq && \
+    apt-get install -y --no-install-recommends \
+        curl ca-certificates unzip bsdmainutils python3 \
+        less ncurses-bin build-essential pkg-config libssl-dev && \
+    curl -fsSL \
+        "https://github.com/caddyserver/caddy/releases/download/v2.9.1/caddy_2.9.1_linux_amd64.tar.gz" \
+        | tar -xz -C /usr/local/bin caddy && \
+    chmod +x /usr/local/bin/caddy && \
+    curl -fsSL \
+        "https://github.com/duckdb/duckdb/releases/download/v1.5.1/duckdb_cli-linux-amd64.zip" \
+        -o /tmp/duckdb.zip && \
+    unzip /tmp/duckdb.zip -d /usr/local/bin && \
+    chmod +x /usr/local/bin/duckdb && \
+    rm /tmp/duckdb.zip && \
+    duckdb :memory: "INSTALL httpfs;" && \
+    curl -fsSL "https://github.com/tsl0922/ttyd/releases/latest/download/ttyd.x86_64" \
+        -o /usr/local/bin/ttyd && \
+    chmod +x /usr/local/bin/ttyd
+
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && \
+    apt-get clean && rm -rf /var/lib/apt/lists/*
+
+ENV PATH="/root/.cargo/bin:${PATH}" \
+    LANG=C.UTF-8 \
+    LC_ALL=C.UTF-8
+
+WORKDIR /app
+
+COPY data/basedosdados.duckdb shell/Caddyfile shell/auth.py start.sh ./
+COPY ask/ask /app/ask
+RUN chmod +x start.sh /app/ask
+
+EXPOSE 8080
+
+ENTRYPOINT ["./start.sh"]