feat: add x and y medians to plot

[brunorosilva]

Fixes #181

Describe your changes

Compute the median values for x and for y using the pd.Series.median method.
Added median to the get_values docstring.

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).

[github-actions]

Congratulations on making your first pull request to Data Morph! Please familiarize yourself with the contributing guidelines, if you haven't already.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.47%. Comparing base (1f7779c) to head (41591fd).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #188   +/-   ##
=======================================
  Coverage   98.47%   98.47%           
=======================================
  Files          43       43           
  Lines        1839     1841    +2     
  Branches      114      114           
=======================================
+ Hits         1811     1813    +2     
  Misses         25       25           
  Partials        3        3           

Files with missing lines	Coverage Δ
src/data_morph/data/stats.py	100.00% <ø> (ø)
src/data_morph/plotting/static.py	100.00% <100.00%> (ø)
tests/data/test_stats.py	100.00% <100.00%> (ø)

[stefmolin]

I'm running this on multiple different shapes to make sure this doesn't constrict things, but I do have some comments for now.

The statistics here are way too close together it is hard to read. Can we space them out more vertically?

[stefmolin]

I much prefer Oxford commas, so let's change this to this:

Suggested change

	Named tuple consisting of mean, median and standard deviations of x and y,
	Named tuple consisting of mean, median, and standard deviations of x and y,