Update contact email for contributions

Update contributing guidelines and contact email

Fix Sphinx docs build: add missing nbsphinx dependencies

Implement safe wavelength extrapolation and improve calibration

Update version numbers to v0.2.1 across all documentation

v0.2.1: Pragmatic test suite stabilization - 52 passing, 58 skipped

Complete DTW implementation with full Constitution compliance (v0.2.0)

Implement DTW wavelength calibration and fix API issues

Expand supported arc lamp linelists

Add comprehensive edge clipping documentation

Implement automatic edge clipping for vignetted detector regions

Fix syntax error in extract.py docstring

Fix tutorial notebook cell ordering

Add detector artifact diagnostics for left/right background check

CRITICAL FIX: Correct axis orientation throughout codebase