This release fixes important bugs, and adds new functionality:
* Adds support for hyperfine structure calculations (many thanks to jonathanpritchard 87 ) - see [ARC_3_1_Additions.ipynb](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/blob/master/doc/ARC_3_1_Additions.ipynb) or [ARC_3_1_Additions.html](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/blob/master/doc/_static/ARC_3_1_Additions.html) for more details
* Fixes bug that caused low-ell states not to be included when calculating quadrupole-quadrupole interactions in the PairStateInteractions (many thanks to SylvainDLDK 81 )
* Fixes wrong energy units returned by StarkMap.getState (many thanks to Dobrzyniecki 85 )
* Improves precision of high \ell states by incorporating scalling of quantum defects for \ell >4 (many thanks to rbrown137 80)
* Adds support for formatting SI prefixes in LevelPlot (many thanks to petermao 71 )