make subtree "split" overhaul

In order to create cleaner histories we should be using subtree split
and push in order to preview the changes as an MR before pushing to
main.

.gitlab/Makefile

@@ -0,0 +1,36 @@
+SHELL := /bin/bash
+
+VERSION ?= $(shell cat VERSION)
+IMAGE ?= $(shell cat IMAGE):$(VERSION)
+IMAGE_LATEST ?= $(shell cat IMAGE):latest
+PWD ?= $(shell pwd)
+STASH ?= "common-update-stash"
+
+include .gitlab/make/docker.makefile
+include .gitlab/make/helm.makefile
+include .gitlab/make/kaniko.makefile
+include .gitlab/make/truenas.makefile
+include .gitlab/make/git.makefile
+
+.PHONY: warning
+warning:
+	@printf "Running a potentially destructive command. If a conflict occurs, fix the conflict and re-run the command.\n"
+	@printf "Cancel with ctrl + c within 3 seconds."
+	@sleep 3
+
+.PHONY: make-stash-drop
+make-stash-drop:
+	@if [ ! -z "$$(git stash list | grep -r 'stash@{0}.*common')" ]; then git stash drop; fi
+
+.PHONY: make-update
+make-update:
+	-git remote add common git@gitlab.ducoterra.net:services/common.git
+	-git subtree pull --prefix .gitlab --message "Merge update from Common" -q git@gitlab.ducoterra.net:services/common.git main
+
+.PHONY: make-push
+make-push: warning
+	@make make-update
+	@git remote add common git@gitlab.ducoterra.net:services/common.git
+	@git subtree split --branch common-minecraft --prefix .gitlab
+	@git subtree push --prefix .gitlab common main
+	@git remote remove common