Add feeds for new category

[shadil-rayyan]

Description

We are adding a new category: <CATEGORY NAME> (e.g., System Design, Android Development, Developer Newsletters).
Contributors are invited to add high-quality RSS/Atom feeds for this category.

Important:

• No AI-specific content.
• Only high-quality developer blogs, newsletters, or system design resources.
• Each feed must have a valid xmlUrl. Optional: htmlUrl for the human-readable blog link.

Steps to Contribute

1. Open feeds.xlsx in Excel or Google Sheets.

2. Add at least 5 feeds under the new category. Include:

   • category → <CATEGORY NAME>
   • title → Name of the site/newsletter
   • xmlUrl → RSS/Atom feed link (required)
   • htmlUrl → Optional, human-facing blog link

3. Run the conversion script:

   node convertExcelToJson.js

   This generates feeds.json with your updates.

4. Test OPML generation (optional, recommended).

5. Submit a Pull Request with:

   • Updated feeds.xlsx
   • Updated feeds.json

Notes

• Ensure all feeds are working and publicly accessible.
• Categorize properly so users can easily find them in the OPML.
• Keep formatting consistent with existing entries.