Generate flag types (again?)

Closes #1381

Makefile

@@ -0,0 +1,40 @@
+# NOTE: this Makefile is meant to provide a simplified entry point for humans to
+# run all of the critical steps to verify one's changes are harmonious in
+# nature. Keeping target bodies to one line each and abstaining from make magic
+# are very important so that maintainers and contributors can focus their
+# attention on files that are primarily Go.
+
+.PHONY: all
+all: generate lint tag-test test check-bin tag-check-bin gfmrun toc
+
+.PHONY: generate
+generate:
+	go run internal/build/build.go generate
+
+.PHONY: lint
+lint:
+	go run internal/build/build.go vet
+
+.PHONY: tag-test
+tag-test:
+	go run internal/build/build.go -tags urfave_cli_no_docs test
+
+.PHONY: test
+test:
+	go run internal/build/build.go test
+
+.PHONY: check-bin
+check-bin:
+	go run internal/build/build.go check-binary-size
+
+.PHONY: tag-check-bin
+tag-check-bin:
+	go run internal/build/build.go -tags urfave_cli_no_docs check-binary-size
+
+.PHONY: gfmrun
+gfmrun:
+	go run internal/build/build.go gfmrun docs/v2/manual.md
+
+.PHONY: toc
+toc:
+	go run internal/build/build.go toc docs/v2/manual.md