Add a `merge` algorithm for combining sorted sequences#193

Draft

mdznr wants to merge 4 commits intoapple:mainfrom

Commits on Dec 28, 2022

Add a basic merge algorithm implementation
Matt Zanchelli
committed
WIP guide
Matt Zanchelli
committed
Add `underestimatedCount` and `count`
Matt Zanchelli
committed
Add `isEmpty` implementation
Matt Zanchelli
committed