feat: add preliminary docker-compose and default .env

.env.default

@@ -0,0 +1,21 @@
+# ========== Global config ==========
+
+
+# ============= Backend =============
+BACKEND_PORT=6567              # Port on which the backend service should listen to requests.
+
+# Postgres and TypeORM
+PG_USER=kitty
+PG_PASS=CHANGEME
+PG_HOST=127.0.0.1
+PG_PORT=5432
+PG_DB=kittyurl
+
+# Site info
+PUBLIC_URL=https://example.com # Publicly accessible website root, used for rewrites. Note there is no trailing slash in the URL.
+IS_PROXIED=false               # Set to `true` if behind a reverse proxy, like apache/nginx.
+USE_SUBDOMAINS=true            # Whether to use subdomains for URL generation.
+DEBUG=false                    # Set to `false` to disable some features not meant to be seen publicly (like swagger documentation).
+
+# ============  Frontend ============
+FRONTEND_PORT=6568             # Port on which the frontend service should listen to requests.