feat: allow containerized deployments

At the moment, it seems like it should be working, but I get:
```
lua5.1: error loading module 'bcrypt' from file '/usr/local/openresty/luajit/lib/lua/5.1/bcrypt.so':
	Error relocating /usr/local/openresty/luajit/lib/lua/5.1/bcrypt.so: luaL_setfuncs: symbol not found
```

docker-compose.yaml

@@ -0,0 +1,13 @@
+# Generate a random secret key
+# export PROD_SECRET_KEY=$(openssl rand -hex 32)
+# Start the container
+# docker-compose up
+version: "3"
+services:
+  porom:
+    build: 
+      context: .
+      args:
+        - PROD_SECRET_KEY=${PROD_SECRET_KEY}
+    ports: 
+      - "8080:8080"

dockerfile

@@ -0,0 +1,36 @@
+# HOW TO:
+#
+# Generate a random secret key & build the Docker image
+# ```sh
+# SECRET_KEY=$(openssl rand -hex 32) docker build --build-arg PROD_SECRET_KEY="$SECRET_KEY" -t porom:latest .
+# ```
+#
+# Then run the container
+# ```sh
+# docker run -d -p 8080:8080 --name porom porom:latest
+# ```
+#
+FROM openresty/openresty:alpine-fat
+COPY ./nginx.conf /usr/local/openresty/nginx/conf/nginx.conf
+COPY . /usr/local/openresty/nginx/html
+WORKDIR /usr/local/openresty/nginx/html
+RUN apk add --no-cache \ 
+    make \
+    git \
+    make \
+    gcc \
+    g++ \
+    musl-dev \
+    libffi-dev \
+    openssl-dev \
+    sqlite-dev \
+    imagemagick-dev \
+    lua5.1 \
+    lua5.1-dev
+RUN eval "$(luarocks --lua-version 5.1 path)"
+RUN luarocks --lua-version 5.1 build --only-deps
+ARG PROD_SECRET_KEY
+RUN echo "return { key = \"${PROD_SECRET_KEY}\",}" > /usr/local/openresty/nginx/html/secrets.lua
+EXPOSE 8080
+RUN chmod +x /usr/local/openresty/nginx/html/start.sh
+ENTRYPOINT ["/usr/local/openresty/nginx/html/start.sh", "production"]