Update for pdrtpy version 2.6.4

What's Changed

• Checkconflict by @mpound in #7
• 6 now that av fitting is available in h2 excitation fitting we need an example in the documentation by @mpound in #8

New Contributors

• @mpound made their first contribution in #7

Full Changelog: 2.2.9...v2.6.4

v2.2.9

notebooks updated for pdrtpy version 2.2.9. New notebook for adding models.

Version 2.1.1

For use with pdrtpy version 2.1.1