Package extension for Unitful.jl

[brainandforce]

This should resolve #26 by providing an package extension for interoperability with Unitful.jl.

Features provided by this extension include:

• Implementation of the wedge product for Quantity types, including Quantity{Real}
• Better printing for Quantity{<:AbstractCliffordNumber}
• Error messages when attempting to construct an AbstractCliffordNumber{Q,Quantity} (this is disallowed because Quantity does not subtype Real or Complex)

Some extra features will likely be added before the next release; this is just the initial implementation of the extension.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.54%. Comparing base (9c9ccc0) to head (fd93a9c).
Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #28      +/-   ##
==========================================
+ Coverage   88.22%   88.54%   +0.31%     
==========================================
  Files          19       20       +1     
  Lines         790      812      +22     
==========================================
+ Hits          697      719      +22     
  Misses         93       93              

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