Add make targets for common checks + fixes

This is to make it easier for existing and new maintainers and contributors to run checks on the codebase.

Makefile

@@ -0,0 +1,18 @@
+fmtcheck:
+	"$(CURDIR)/scripts/gofmtcheck.sh"
+
+fmtfix:
+	gofmt -w ./
+
+vetcheck:
+	go vet ./...
+
+copyrightcheck:
+	go run github.com/hashicorp/copywrite@latest headers --plan
+
+copyrightfix:
+	go run github.com/hashicorp/copywrite@latest headers
+
+check: copyrightcheck vetcheck fmtcheck
+
+fix: copyrightfix fmtfix

scripts/gofmtcheck.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: MPL-2.0
+
+if [[ -n $(gofmt -l ./) ]]; then echo "Please run gofmt -w ./ to format code"; exit 1; fi;