stdout not being captured

[JackDunnNZ]

On the current master, the following doesn't show any output being captured

```@example
println("hello world")
```

Works as expected on 0.21.5

[mortenpi]

Seems to be due to #938. We're just discarding the buffer variable now:

Documenter.jl/src/Expanders.jl

Lines 532 to 571 in 9d30975

	result, buffer = nothing, IOBuffer()
	if !continued # run the code
	# check if there is any code wating
	if haskey(page.globals.meta, :ContinuedCode) && haskey(page.globals.meta[:ContinuedCode], sym)
	code = page.globals.meta[:ContinuedCode][sym] * '\n' * x.code
	delete!(page.globals.meta[:ContinuedCode], sym)
	else
	code = x.code
	end
	for (ex, str) in Utilities.parseblock(code, doc, page; keywords = false)
	(value, success, backtrace, text) = Utilities.withoutput() do
	cd(dirname(page.build)) do
	Core.eval(mod, ex)
	end
	end
	Core.eval(mod, Expr(:global, Expr(:(=), :ans, QuoteNode(value))))
	result = value
	print(buffer, text)
	if !success
	push!(doc.internal.errors, :example_block)
	@warn("""
	failed to run `@example` block in $(Utilities.locrepr(page.source, lines))
	```$(x.language)
	$(x.code)
	```
	""", value)
	page.mapping[x] = x
	return
	end
	end
	else # store the continued code
	CC = get!(page.globals.meta, :ContinuedCode, Dict())
	CC[sym] = get(CC, sym, "") * '\n' * x.code
	end
	# Splice the input and output into the document.
	content = []
	input = droplines(x.code)
	# Generate different in different formats and let each writer select
	output = Base.invokelatest(Utilities.display_dict, result)

Looking into a fix.

[JackDunnNZ]

Thanks @mortenpi !