docs(config): add runtime config and environment variables section

[Hebilicious]

🔗 Linked issue

Extracted from #1547

❓ 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

📝 Checklist

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

[codecov]

Codecov Report

Merging #1550 (94eeb86) into main (a949cb9) will not change coverage.
The diff coverage is n/a.

❗ Current head 94eeb86 differs from pull request most recent head 2475bd4. Consider uploading reports for the commit 2475bd4 to get more accurate results

@@           Coverage Diff           @@
##             main    #1550   +/-   ##
=======================================
  Coverage   76.47%   76.47%           
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  Files          73       73           
  Lines        7591     7591           
  Branches      757      757           
=======================================
  Hits         5805     5805           
  Misses       1785     1785           
  Partials        1        1           

[pi0]

Thanks for nice and elegant PR ❤️ (i have made few refactors hope are fine to you)