Add spiral target shape

[nickc6424]

Fixes #177

Describe your changes Added Spiral target shape

Checklist

• [x] Test cases have been modified/added to cover any code changes.
• [x] Docstrings have been modified/created for any code changes.
• [x] All linting and formatting checks pass (see the contributing guidelines for more information).

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 98.42%. Comparing base (51b8d26) to head (dbc4e76). Report is 53 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #192   +/-   ##
=======================================
  Coverage   98.42%   98.42%           
=======================================
  Files          43       43           
  Lines        1775     1782    +7     
  Branches      358      357    -1     
=======================================
+ Hits         1747     1754    +7     
  Misses         25       25           
  Partials        3        3           

Files with missing lines	Coverage Δ
src/data_morph/shapes/factory.py	100.00% <ø> (ø)
src/data_morph/shapes/points.py	100.00% <100.00%> (ø)
tests/shapes/test_points.py	100.00% <100.00%> (ø)

[stefmolin]

Superseded by #264.