Added more examples and pgsql reader

Makefile

@@ -1,4 +1,4 @@
-.PHONY: all build test lint coverage clean install help
+.PHONY: all build test lint coverage clean install help docker-up docker-down docker-test docker-test-integration
 
 # Binary name
 BINARY_NAME=relspec
@@ -58,5 +58,36 @@ deps: ## Download dependencies
 	$(GOMOD) tidy
 	@echo "Dependencies updated"
 
+docker-up: ## Start PostgreSQL test database
+	@echo "Starting PostgreSQL test database..."
+	@if command -v docker-compose > /dev/null 2>&1; then \
+		docker-compose up -d postgres; \
+	else \
+		docker compose up -d postgres; \
+	fi
+	@echo "Waiting for PostgreSQL to be ready..."
+	@sleep 3
+	@echo "PostgreSQL is running on port 5433"
+	@echo "Connection: postgres://relspec:relspec_test_password@localhost:5433/relspec_test"
+
+docker-down: ## Stop PostgreSQL test database
+	@echo "Stopping PostgreSQL test database..."
+	@if command -v docker-compose > /dev/null 2>&1; then \
+		docker-compose down; \
+	else \
+		docker compose down; \
+	fi
+	@echo "PostgreSQL stopped"
+
+docker-test: ## Run PostgreSQL integration tests with Docker
+	@./tests/postgres/run_tests.sh
+
+docker-test-integration: docker-up ## Start DB and run integration tests
+	@echo "Running integration tests..."
+	@sleep 2
+	@RELSPEC_TEST_PG_CONN="postgres://relspec:relspec_test_password@localhost:5433/relspec_test" \
+		$(GOTEST) -v ./pkg/readers/pgsql/ -count=1 || (make docker-down && exit 1)
+	@make docker-down
+
 help: ## Display this help screen
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-20s\033[0m %s\n", $$1, $$2}'