docs(totp): add string secrets and authenticator compatibility notes to README

[yeojz]

Summary

• Adds With raw string secrets subsection under generate usage, showing stringToBytes from @otplib/core for plain passphrase secrets and @otplib/plugin-base32-alt bypass plugins (bypassAsString, bypassAsHex, bypassAsBase64) for hex/base64-encoded secrets
• Adds Compatibility with Authenticator Apps section documenting the default parameters (sha1, 6 digits, 30s period, Base32 secret) required for compatibility with Google Authenticator, Authy, Microsoft Authenticator, 1Password, etc.
• Adds authenticator and google-authenticator keywords to package.json

[codecov]

Bundle Report

Bundle size has no change ✅

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	100% (🎯 100%)	1556 / 1556
🔵	Statements	100% (🎯 100%)	1577 / 1577
🔵	Functions	100% (🎯 100%)	346 / 346
🔵	Branches	100% (🎯 100%)	824 / 824

File Coverage

No changed files found.

Generated in workflow #343 for commit ea5a1d9 by the Vitest Coverage Report Action

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (5d88575) to head (ea5a1d9).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #813   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           59        59           
  Lines         1996      1996           
  Branches       404       428   +24     
=========================================
  Hits          1996      1996           

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