Update .gitattributes to use LFS for PDF, DOCX, and PPTX files; simplify workflow for pushing to Hugging Face

Remove XET LOCK comment from .gitattributes for clarity

Reorganize XET LOCK section in .gitattributes for clarity

Add comment header for XET LOCK in .gitattributes

Refactor .gitattributes for git-xet and update workflow to add upstream remote

Update .gitattributes and workflow to configure git-xet for binary storage on Hugging Face

Add LFS support for various file types in .gitattributes

Remove LFS for PDFs; store as regular files

Initial commit