getting_started.py now demonstrates how to use common cmd2 deocrators

[tleonhardt]

getting_started.py now demonstrates how to use both the @with_argparser and @with_annotated decorators for defining command arguments.

The intent is to help make the getting_started.py example something of a one-stop shop to quickly orient new cmd2 users to what we view as best practices. It was previously parsing raw Statements for arguments, which frankly I view as an antipattern.

Closes #1704

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.59%. Comparing base (a442a0d) to head (b763f19).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1705      +/-   ##
==========================================
+ Coverage   99.57%   99.59%   +0.01%     
==========================================
  Files          23       23              
  Lines        5894     5894              
==========================================
+ Hits         5869     5870       +1     
+ Misses         25       24       -1     

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unittests	99.59% <ø> (+0.01%)	⬆️

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[tleonhardt]

@kmvanbrunt I would appreciate any constructive feedback on how to improve the @with_argparser example here to make it more educational for new users.

@KelvinChung2000 I would appreciate any constructive feedback on how to improve the @with_annotated example here to make it more educational for new users.

[KelvinChung2000]

I recommend demonstrating an example with a positional Path type.

@cmd2.with_annotated
def do_cat(
    self,
    path: pathlib.Path,
    numbered: Annotated[
        bool, Option("-n", "--number", help_text="prefix each line with its number")
    ] = False,
) -> None:
    """Print a file's contents. `path` tab-completes filesystem paths automatically.

    Try:
        cat <TAB>              # path completes files/dirs -- no completer wired
        cat notes.txt
        cat notes.txt -n       # -n / --number, declared via Option metadata
        cat notes.txt --no-number
    """
    for index, line in enumerate(path.read_text().splitlines(), start=1):
        self.poutput(f"{index}: {line}" if numbered else line)

This demonstrates auto-completer inference and non-built-in type support while being simple and explicit. But this does not fit a "intro" command very well.

[tleonhardt]

@KelvinChung2000 I took your advice and added a modified version of your cat command example for demonstrating use of the @with_annotated decorator.

I also reverted the do_intro command logic to its previous state.