Linux

There's no particularly smart way to accomplish this in the exact way that you want. I don't like the solution which searches your $PATH because now you're adding latency to search your entire $PATH for every command to add this functionality. It's a singularly better solution to tell the CLI what you want versus the CLI attempting (using logic) to figure it out.

The easiest solution here is to create your own command which calls the target application with --help;

#!/bin/bash
$1 --help | bat --language=help

Then run it;

$ script_name docker

and it will run docker --help | bat --language=help. If you use this solution a lot you can try to use bash function which you call at the end of commands if they error;

helpfunc() {
  $1 --help | bat --language=help
}

trap 'helpfunc' ERR

But now you have to run logic to truncate previous commands to only return the first word of a command from history and it becomes a real PITA...

Long story short, if you want to hack your console experience like this, you're looking for a functional shell scripting language, like Elvish shell and not bash.