W-19149055: Edit messages for the 10 new "orchestrator" commands

[jshackell-sfdc]

What does this PR do?

Edits messages

What issues does this PR fix or reference?

@W-19149055@

Overview of suggested changes

Here's a bit of info about what I did, and why. (This section was written by a human (Juliet) and not AI. )

• Added text to --target-org summary about it not being required if the user set the target-org config var; this makes it consistent with the same flag summary in other CLI commands.
• Removed -target-org descriptions, because they duplicated what was already in the command description (about perms, etc) (but see note below)
• In general, removed any flag descriptions that were duplicates of the summary and provided no more information. (but see note below)
• In examples, removed unnecessary quotes, left only those where the flag value had a space. I think this makes the examples cleaner/easier to read.
• Removed list of valid and default values from flag descriptions, because they're automatically displayed in the help, so no need to duplicate info.
• Made a few little minor edits, mostly around using contractions and adding periods.

NOTE: If only some flags have explicit descriptions, they're listed in the FLAG DESCRIPTIONS section, but this section won't also include the flags that don't have descriptions. Some people find this confusing (understandably). This was a design decision that we made back when sf was first developed. In hindsight, it might not have been the right decision, and maybe one day we'll change it. But for now, the CLI team has other priorities, so that's how it will stay. If you don't like how this works, then put the descriptions back, I totally understand 🙂.

Thanks for such awesome messages -- they're so helpful!