[EXP] Release v0.3.0

What's Changed

• Check box version is the latest or not when run box self-update by @huangdijia in #36
• fixed some typos by @MichonneHsu in #42
• Adds phpstan package and box phpstan proxy command by @huangdijia in #41
• Adds pint package and box pint proxy command by @huangdijia in #40
• Release v0.3.0 by @huangzhhui in #43

New Contributors

• @MichonneHsu made their first contribution in #42

Full Changelog: v0.2.0...v0.3.0