DOC: inline docstring for pandas.plotting functions

[KevsterAmp]

• closes DOC: Replace @Appender, @Substitution, @doc with inlined docstrings #62437 (Replace xxxx with the GitHub issue number)
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations to new arguments/methods/functions.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

Removed @Appender and @Substition on the following functions:

• pandas.plotting.boxplot
• pandas.plotting.boxplot_frame
• pandas.plotting.PlotAccessor.line
• pandas.plotting.PlotAccessor.bar
• pandas.plotting.PlotAccessor.barh

[KevsterAmp]

pre-commit.ci autofix

[KevsterAmp]

Should I also remove the following since its not accessed by any functions after removing @Appender and @Substition on pandas/plotting/_core.py:

• pandas/pandas/plotting/_core.py

  Line 279 in b20d6ab

  _boxplot_doc = """

• pandas/pandas/plotting/_core.py

  Line 445 in b20d6ab

  _backend_doc = """\

• pandas/pandas/plotting/_core.py

  Line 454 in b20d6ab

  _bar_or_line_doc = """

[mroeschke]

Should I also remove the following since its not accessed by any functions after removing @Appender and @Substition on pandas/plotting/_core.py:

* https://github.com/pandas-dev/pandas/blob/b20d6ab6b6ad80ec68361321878b6a2fac272d82/pandas/plotting/_core.py#L279

* https://github.com/pandas-dev/pandas/blob/b20d6ab6b6ad80ec68361321878b6a2fac272d82/pandas/plotting/_core.py#L445

* https://github.com/pandas-dev/pandas/blob/b20d6ab6b6ad80ec68361321878b6a2fac272d82/pandas/plotting/_core.py#L454

yes

[mroeschke]

I don't think the indentations of the See Alsos in your PR are correct

[mroeschke]

Thanks @KevsterAmp