Port over release script

Co-Authored-By: Kevin McConnell <kevin@37signals.com>

Dockerfile-export

@@ -0,0 +1,17 @@
+# syntax = docker/dockerfile:1
+
+# Make sure it matches the Ruby version in .ruby-version and Gemfile
+ARG RUBY_VERSION=3.4.7
+FROM ruby:$RUBY_VERSION-slim as base
+
+# Install the tools we need
+RUN apt update && apt install -y zip
+
+# Export from this folder
+WORKDIR /campfire
+
+# Copy application code
+COPY . .
+
+# Create the archive
+CMD ["zip", "-r", "/campfire.zip", "."]