v0.19.0

What's Changed

• chore: bump to Go 1.21 by @rootulp in #230
• docs: add a table for alternative implementations by @rootulp in #229
• refactor(pb/proof.go)!: converting pb definition to use snake_case by @distractedm1nd in #232

Full Changelog: v0.18.1...v0.19.0