chore: add ftlDebug script (#2742)

This makes it easy to run FTL under dlv, and dlv will wait for the IDE
to attach. This is useful if you want to debug commands other than ftl
dev

scripts/ftlDebug

@@ -0,0 +1,13 @@
+#!/bin/bash
+# Note that this does not seem to work in intellij, as it can't handle dlv without --continue
+# VS Code works great though
+set -euo pipefail
+ftldir="$(dirname "$(readlink -f "$0")")/.."
+name="ftl"
+dest="${ftldir}/build/devel"
+src="./cmd/${name}"
+if [ "${name}" = "ftl" ]; then
+  src="./frontend/cli"
+fi
+mkdir -p "$dest"
+(cd "${ftldir}/${src}" && dlv debug --headless --listen=:2345 --api-version=2 --log --accept-multiclient -- "$@" )