Add Makefile for standardized build and deployment

Description

This repository is missing a Makefile which is used across the Open Horizon Services organization for standardized build, test, and deployment workflows.

Proposed Solution

Add a Makefile based on the examples from existing repositories:

• service-fledge/Makefile
• service-homeassistant/Makefile

Requirements

The Makefile should include common targets such as:

• init - Initialize the development environment
• build - Build the service/container
• run - Run the service locally
• test - Run tests (if applicable)
• clean - Clean up build artifacts
• publish - Publish to Open Horizon (if applicable)
• check - Display environment variables and configuration

Benefits

• Standardizes the build process across all services
• Makes it easier for contributors to build and test locally
• Improves documentation through self-documenting make targets
• Facilitates CI/CD integration

Additional Context

This issue was created as part of a repository audit to ensure consistency across the open-horizon-services organization.

Labels

• good first issue - Great for new contributors
• help wanted - Community contributions welcome
• hacktoberfest - Eligible for Hacktoberfest participation