Fix copy-paste "format: binary" error

[handrews]

Fixes#4293

These examples got copied from 3.0.4 and apparently I forgot to adjust them for 3.1.1 and no one else noticed.

[ralfhandl]

Lgtm

[mikekistler]

Looks good. 👍

I left some comments to add contentEncoding in places where I thought it added clarity. When I first read this line:

default for a string without contentEncoding is text/plain

my thought was "default what"? So my changes are intended to fix that but I'll defer to your judgement to decide if this is necessary.

[mikekistler]

Could we instead say:

Suggested change

	# default for a string without `contentEncoding` is `text/plain`
	# default `contentEncoding` for a string is `text/plain`

[handrews]

@mikekistler no, because text/plain is a content type (Encoding Object contentType, or alternatively Schema Object contentMediaType) and not a content encoding (Schema Object contentEncoding, or alternatively Encoding Object headers field, header Content-TransferEncoding) which is something like "base64"

But we could say:

# default content type for a string without `contentEncoding` is `text/plain`

so I'll do that. I totally see how you read it the way you did and I had to think a moment before realizing what was wrong with it.

[mikekistler]

and

Suggested change

	# default for arrays is based on the type in the `items`
	# default `contentEncoding` for arrays is based on the type in the `items`

[mikekistler]

and

Suggested change

	# No Encoding Object, so use default `text/plain`
	# No Encoding Object, so use default `contentEncoding` `text/plain`

[mikekistler]

and maybe

Suggested change

	# Encoding Object overrides the default `application/json`
	# Encoding Object overrides the default `contentEncoding` `application/json`