SkillGraph v1.0.0

What's Changed

• feat(etl)!: merge duplicate skills, data-v4 and model-v4 by @AtulACleaver in #41
• docs(stats): stats.json, stats.md and report figures by @AtulACleaver in #43
• docs: final README and cleanup by @AtulACleaver in #44

Full Changelog: data-v4...v1.0.0