Add -p short flag for pretty command

[AmosOO7]

Description

This PR adds a short -P flag as an alias for the existing --pretty option to make the command easier and faster to use.

This closes #226

Notes to the reviewers

The new -P flag behaves exactly the same as --pretty.
No existing behavior is changed — this only introduces an additional alias.

Changelog notice

Added -P as a shorthand flag for the pretty command.

Checklists

All Submissions:

• I've run cargo fmt and cargo clippy
• I followed the contribution guidelines

[coveralls]

Pull Request Test Coverage Report for Build 20858395002

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 7.901%

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Totals
Change from base Build 20714655583:	0.0%
Covered Lines:	172
Relevant Lines:	2177

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💛 - Coveralls

[tvpeter]

Hi @AmosOO7,

Thank you for working on this. However, your suggestion of using an uppercase "P" does not align with the short naming convention used throughout the codebase. It would be more suitable to use a different letter, as seen in some instances in the code.

As an alternative, I would suggest using h for "human-readable form". If you can think of a better option, please feel free to update it, and I'll review it again.

Thank you!

[AmosOO7]

Thank you for taking a look at the @tvpeter, I don't think h will work, as it is universally reserved for help (--help).
Which is why I suggest using j since the output is in json format

[va-an]

Will this still be relevant after #234?
Completions work for all commands and arguments, including --pretty.