Zfel

What's Changed
* legacy master by ChristopherMayes in https://github.com/slaclab/zfel/pull/7


**Full Changelog**: https://github.com/slaclab/zfel/compare/v0.9.1...v0.9.1a

What's Changed
* Refactor of internal routines by ChristopherMayes in https://github.com/slaclab/zfel/pull/3

New Contributors
* ChristopherMayes made their first contribution in https://github.com/slaclab/zfel/pull/3

**Full Changelog**: https://github.com/slaclab/zfel/compare/v0.99...v0.9.0