Migrate to ESM and allow readonly arrays

[targos]

• refactor: migrate to ESM-only
• feat: allow parsing readonly arrays

[codecov]

Codecov Report

❌ Patch coverage is 95.34884% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.66%. Comparing base (f424c4e) to head (c038a90).
⚠️ Report is 10 commits behind head on main.

Files with missing lines	Patch %	Lines
src/parse/createFieldParser.ts	87.50%	1 Missing ⚠️
src/parsers/parseDocumentNumberOptional.ts	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #64      +/-   ##
==========================================
- Coverage   89.46%   88.66%   -0.80%     
==========================================
  Files          44       48       +4     
  Lines         389      450      +61     
  Branches       99      123      +24     
==========================================
+ Hits          348      399      +51     
- Misses         41       51      +10     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.