CLI updates

[stefmolin]

• Add --start and --target shorthand for --start-shape and --target-shape
• Rename --ramp-in and --ramp-out ease* everywhere
• Add --ease flag as a shorthand for --ease-in --ease-out
• Add -o as a shorthand for --output-directory

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.49%. Comparing base (5f51726) to head (a95e082).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #269   +/-   ##
=======================================
  Coverage   98.49%   98.49%           
=======================================
  Files          60       60           
  Lines        1922     1925    +3     
  Branches      112      113    +1     
=======================================
+ Hits         1893     1896    +3     
  Misses         26       26           
  Partials        3        3           

Files with missing lines	Coverage Δ
src/data_morph/cli.py	100.00% <100.00%> (ø)
src/data_morph/morpher.py	100.00% <100.00%> (ø)
tests/test_cli.py	100.00% <100.00%> (ø)
tests/test_morpher.py	100.00% <100.00%> (ø)