Fix typo in sampler documentation
Fixes a small typo in the docs when listing nessai
in the available samplers: https://lscsoft.docs.ligo.org/bilby/samplers.html#nested-samplers
Fixes a small typo in the docs when listing nessai
in the available samplers: https://lscsoft.docs.ligo.org/bilby/samplers.html#nested-samplers