Bump up the version to 1.0.0-alpha02

[jingtang10]

DO NOT MERGE until ready for release

For alpha02, I think we should merge:

• Use surrogates to de/serialize sealed interfaces #26
• Fix equality check for non-data classes #37
• Expose kotlinx-datetime library as api #39
• Refactor enum class code generation #44

It's a good idea to open an issue first for discussion.

• Tests pass
• Appropriate changes to documentation are included in the PR