Add units to docs

[karllark]

Closes #219.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.89%. Comparing base (a1cae59) to head (732d5a4).
Report is 38 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #227   +/-   ##
=======================================
  Coverage   99.89%   99.89%           
=======================================
  Files           8        8           
  Lines         919      919           
=======================================
  Hits          918      918           
  Misses          1        1           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[mdecleir]

Looks great!