PySDM v2.86

What's Changed

• remove unrelated settings from Arabas_et_al_2015 definitions by @slayoo in #1371
• Fix link to PySDM-examples package in PySDM README.md by @AgnieszkaZaba in #1440
• switch to dark mode for docs by @slayoo in #1444
• add a HOWTO notebook depicting how to manage units in PySDM by @AgnieszkaZaba in #1443

kudos @Sfonxu for suggesting and finding a way how to do dark mode in the docs!

Full Changelog: v2.85...v2.86