Arrow releases stable 1.2.0 version

We're excited to announce the stable Arrow 1.2.0 version. To briefly summarize, this release:

• Improves the API for typed errors, including withError and merge.
• Adds NonEmptyCollection as common parent of NonEmptyList and NonEmptySet.
• Introduces arrow-core-serialization to be used alongside KotlinX Serialization.
• Fixes a few issues found in the Release Candidate.

Read more details in the full Arrow 1.2.0 release announcement.