Delete textile content files

Remove all textile content files from the repository. These files have
already been converted to MDX format and are no longer needed.

Deleted:
- content/partials/ directory (96 textile files)
- index.textile

The content now exists exclusively in MDX format. Build continues to
work with 241 pages generated from MDX sources.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: kennethkalmer