v0.2.0

Changes

• Merge pull request #34 from arceos-hypervisor/lic (0ba3102)
• chore: bump version to 0.2.0 (eaf3639)
• chore: relicense to Apache-2.0 only (2292975)
• Merge pull request #33 from arceos-hypervisor/ci (8fe2f6f)
• refactor: modernize Rust syntax and formatting (809bd97)
• refactor: modernize Rust syntax and formatting (799501f)
• ci: update target to x86_64-unknown-none (ef7376a)
• ci: refactor workflows for modular CI/CD pipeline (0b25696)
• ci: refactor workflows for modular CI/CD pipeline (efeb236)