Add Makefile and targets to streamline development and maintenance

- Added targets for cleaning, formatting, linting, vetting, and installing tools.
- Ensured the `help` target is the default and excluded the `all` target from the help message.

Signed-off-by: Ioannis Polyzos <git@ipolyzos.com>

Makefile

@@ -0,0 +1,96 @@
+.POSIX:
+
+export PATH := $(abspath bin/):${PATH}
+
+.PHONY: all
+all: help ## Default target (help)
+
+.PHONY: check-mkcert
+check-mkcert: ## Check if mkcert is installed
+	@which mkcert > /dev/null || (echo "mkcert is not installed. Please install it from https://github.com/FiloSottile/mkcert" && exit 1)
+
+.PHONY: create-certificate
+create-certificate: check-mkcert ## Create a new local certificate if it doesn't exist
+# if the certificate does not exist, create a new one
+	@if [ ! -f src/cmd/run-server/localhost.pem ]; then \
+		echo "* Creating a new certificate"; \
+		cd src/cmd/run-server && mkcert -install && mkcert localhost; \
+	else \
+		echo "* Certificate already exists"; \
+	fi
+
+.PHONY: mod-init
+mod-init: create-certificate ## Initialize go mod
+# if go.mod does not exist, initialize it
+	@if [ ! -f src/go.mod ]; then \
+		echo "* Initializing go mod"; \
+		cd src && go mod init .; \
+	else \
+		echo "* go.mod already exists"; \
+	fi
+
+.PHONY: populate-generated-folder
+populate-generated-folder: mod-init ## Populate the generated folder
+# if the generated folder exist, remove it
+	@if [ -d generated ]; then \
+		rm -rf generated; \
+	fi
+# create the generated folder
+	@cd src && go run ./cmd/generate-v1 --destination ../generated
+
+.PHONY: run-server
+run-server: populate-generated-folder ## Run the server
+	cd src && go run ./cmd/run-server -certificate cmd/run-server/localhost.pem -key cmd/run-server/localhost-key.pem
+
+.PHONY: build-all
+build-all: mod-init ## Build all the binaries
+	@echo "* Building all binaries"
+	@cd src && go build -o ../bin/add-module ./cmd/add-module
+	@cd src && go build -o ../bin/add-provider ./cmd/add-provider
+	@cd src && go build -o ../bin/bump-versions ./cmd/bump-versions
+	@cd src && go build -o ../bin/generate-v0 ./cmd/generate-v1
+	@cd src && go build -o ../bin/run-server ./cmd/run-server
+	@cd src && go build -o ../bin/validate ./cmd/validate
+	@cd src && go build -o ../bin/verify-gpg-key ./cmd/verify-gpg-key
+
+.PHONY: test
+test: mod-init ## Run the tests for all the packages
+	@cd src && go test ./...
+
+.PHONY: clean
+clean: ## Clean generated files and binaries
+# remove all bins under src
+	@rm -rf bin/
+# remove generated folders
+	@rm -rf bin generated
+
+.PHONY: fmt
+fmt: ## Format the Go code
+	@cd src && go fmt ./...
+
+.PHONY: lint
+lint: ## Run static analysis on the code
+	@cd src && golangci-lint run
+
+.PHONY: vet
+vet: ## Examine the code for potential issues
+	@cd src && go vet ./...
+
+.PHONY: install-tools
+install-tools: ## Install necessary development tools
+	@go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+
+.PHONY: help
+help: ## Prints this help message.
+	@echo ""
+	@echo "Opentofu Registry Makefile"
+	@echo ""
+	@echo "Usage: make [target]"
+	@echo ""
+	@echo "The available targets for execution are listed below."
+	@echo ""
+	@echo "Targets:"
+	@awk 'BEGIN {FS = ":.*$$"; OFS = ""} \
+    /^# .*$$/ { doc=$$0; sub(/^# /, "", doc); next } \
+    /^[a-zA-Z0-9_-]+:.*## .*$$/ { target=$$1; sub(/:$$/, "", target); desc=$$0; sub(/^[^#]*## /, "", desc); if (!seen[target]++) { printf "\033[1m%-30s\033[0m %s\n", target, desc } } \
+    /^[a-zA-Z0-9_-]+:.*$$/ { target=$$1; sub(/:$$/, "", target); if (!seen[target]++) { if (doc != "") { printf "\033[1m%-30s\033[0m %s\n", target, doc; doc="" } else { printf "\033[1m%-30s\033[0m\n", target } } }' $(MAKEFILE_LIST)