fix: add exports main field

[AndrewLeedham]

Fixes #433

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (74c7bd8) to head (9e15c45).
⚠️ Report is 2034 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##            master      #434   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            8         8           
  Lines          166       166           
  Branches        57        57           
=========================================
  Hits           166       166           

☔ 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.

[remarkablemark]

Thanks for the contribution @AndrewLeedham. You can find the release here: #436 (comment)