feat: support retryDelay

[Hebilicious]

🔗 Linked issue

unjs/nitro#1534
Resolves #261

❓ Type of change

• 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Implements a retryDelay parameters that default to 100ms.

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[codecov]

Codecov Report

Merging #262 (d35226b) into main (5f95a88) will decrease coverage by 0.12%.
The diff coverage is 85.71%.

❗ Current head d35226b differs from pull request most recent head dece4c7. Consider uploading reports for the commit dece4c7 to get more accurate results

@@            Coverage Diff             @@
##             main     #262      +/-   ##
==========================================
- Coverage   90.47%   90.36%   -0.12%     
==========================================
  Files           5        5              
  Lines         462      467       +5     
  Branches       75       76       +1     
==========================================
+ Hits          418      422       +4     
- Misses         44       45       +1     

Files Changed	Coverage Δ
src/fetch.ts	94.30% <85.71%> (-0.30%)	⬇️

[pi0]

Thanks 💯