Revise short command descriptions.

[mattstein]

Description

Updates Nitro’s short command descriptions for internal consistency, miscellaneous corrections, and consistency with Craft’s console commands.

• Capitalizes proper nouns like Blackfire and Xdebug.
• More accurately describes whether action applies to one or multiple things (Runs Composer commands → Runs a Composer command.)
• More specifically describes a handful of actions.
• Revises format to match Craft’s Remove unused containers → Removes unused containers..
• Updates root command descriptions to align more with getnitro.sh and docs.