v5.2.0

Improved compatibility of types and a couple extra logic guards.

Summary

• Fix broken types in some environments
• Improve separation between mjs and cjs build output
• Use tsc for all builds instead of rollup
• Add additional checks for whether or not a substate exists. This will cause some error paths to begin throwing errors, which is new behavior, but react-substate literally wouldn't have provided any value down these paths anyway, so I'm not marking it as a breaking change.

Full Changelog: v5.1.1...v5.2.0