Add figure eight target shape

[stefmolin]

Fixes #178

Describe your changes

Add figure eight target shape

Checklist

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

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.55%. Comparing base (9391f31) to head (7b92d52).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #265      +/-   ##
==========================================
+ Coverage   98.53%   98.55%   +0.01%     
==========================================
  Files          59       60       +1     
  Lines        1915     1933      +18     
  Branches      112      112              
==========================================
+ Hits         1887     1905      +18     
  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/__init__.py	100.00% <100.00%> (ø)
src/data_morph/shapes/points/figure_eight.py	100.00% <100.00%> (ø)
tests/shapes/test_points.py	100.00% <100.00%> (ø)