Add release script

.gitignore

@@ -2,4 +2,5 @@ target/
 test.db
 server.*
 privkey.pem
-*.jpg
+*.jpg
+wait-for-db-linux*

release.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+
+set -eux -o pipefail
+
+if [ ! -f /proc/sys/fs/binfmt_misc/qemu-aarch64 ]; then
+    docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+fi
+
+docker rm wait_for_db || true
+
+if [ ! -f wait-for-db-linux-amd64 ]; then
+    docker buildx build --platform linux/amd64 --build-arg HOST=x86_64-unknown-linux-musl --tag wait_for_db --output=type=docker .
+    docker run --platform linux/amd64 --name wait_for_db wait_for_db --help
+    docker cp wait_for_db:/wait_for_db wait-for-db-linux-amd64
+    docker stop wait_for_db
+    docker rm wait_for_db
+fi
+
+if [ ! -f wait-for-db-linux-arm64 ]; then
+    docker buildx build --platform linux/arm64 --build-arg HOST=aarch64-unknown-linux-musl --tag wait_for_db --output=type=docker .
+    docker run --platform linux/arm64 --name wait_for_db wait_for_db --help
+    docker cp wait_for_db:/wait_for_db wait-for-db-linux-arm64
+    docker stop wait_for_db
+    docker rm wait_for_db
+fi