first release!

What's Changed

• overdue developments for the Pk multipoles and 2D Pk by @changhoonhahn in #1
• assign2 replaced with assign_quad; FFTperiodic now support weights by @changhoonhahn in #3
• B0(k) implementation for survey geometry by @changhoonhahn in #4

New Contributors

• @changhoonhahn made their first contribution in #1

Full Changelog: https://github.com/changhoonhahn/pySpectrum/commits/v0.1