Improve documentation for field and argument DSL methods

[rmosolgo]

I was hoping that this would play nicer with ruby-lsp. It's better but still not amazing:

Before	After

It's a wall of text, but the docs are there, and if you click to jump to definition, you can read them in original formatting in the gem source.

• Copy docs from Field#initialize to HasFields#field, add tests
• Copy docs from Argument#initialize to HasArguments#argument, add tests
• Check performance impact on schema boot -- this could change how Hashes are allocated during schema definition
• Consider removing Field.from_options?

Fixes #3543 ... almost 5 years later 😞

I'm also interested in exploring other documentation methods if they would play nicer with LSP support.

[rmosolgo]

Using be rake bench:profile_boot, it looks like the code currently allocates way more memory, but way less objects:

- Total allocated: 8242456 bytes (51658 objects)
+ Total allocated: 12990408 bytes (44849 objects)

My guess is that this is Ruby handling all these big keyword argument lists ... time to investigate!

[rmosolgo]

I extracted the Field.from_options change into another PR and reverted my changes to the keyword parameters of these methods because of the memory overhead. But I kept the docs and tests on the docs. In the end, it turned out to use less memory, probably because of removing *args:

- Total allocated: 7770688 bytes (46971 objects)
+ Total allocated: 7685808 bytes (44849 objects)