Improve model description: features, strengths, personal AI benefits

Add citation: developed, built and trained by Swaroop Kallakuri

Rebrand: remove Nanbeige/Swaroop references, zindango-slm only

Update README with Q8_0 GGUF

Add GGUF usage to README

Upload zindango-slm: SFT on Nanbeige4.1-3B for Zindango (English-only)