Bug fixes and efficiency improvements
Along with stability improvements to the shapes of the arrays, a bug was squashed in the `PdgArray` constructor which led to unnecessary reads of a CSV file. This has resulted in a speedup of 3 orders of magnitude for the object constructor, which is used during copying and slicing!
What's Changed
* Patch: ensured contiguity, and consistent shape 85 by jacanchaplais in https://github.com/jacanchaplais/graphicle/pull/86
* Patch: updated agg_op to take strings 87 by jacanchaplais in https://github.com/jacanchaplais/graphicle/pull/88
* Patch docstrings by jacanchaplais in https://github.com/jacanchaplais/graphicle/pull/89
* Migrated FastJet interface to select module by jacanchaplais in https://github.com/jacanchaplais/graphicle/pull/91
* Patch: data structure improvements by jacanchaplais in https://github.com/jacanchaplais/graphicle/pull/94
**Full Changelog**: https://github.com/jacanchaplais/graphicle/compare/0.2.2...0.2.3