Add version command, implement Docker support, make sqlx offline work

DOCKERFILE

@@ -0,0 +1,9 @@
+FROM rust:latest AS builder
+WORKDIR /usr/src/tg-dev-srv-bot
+COPY . .
+RUN SQLX_OFFLINE=true cargo install --path .
+
+FROM debian:bullseye-slim
+RUN apt-get update && apt-get install -y ca-certificates && rm -rf /var/lib/apt/lists/*
+COPY --from=builder /usr/local/cargo/bin/tg-dev-srv-bot /usr/local/bin/tg-dev-srv-bot
+CMD ["tg-dev-srv-bot"]