Suggestion: app$layout should allow non-components

[daattali]

The layout only allows proper Dash components, which makes it cumbersome to add simple text to the page.

It would be helpful if the componentify internal function would allow other simple types like a string, a numeric, a date, a boolean, etc.

It would transform this:

app$layout(list(htmlSpan("My app"), htmlBr(), htmlSpan("By Dean Attali"), htmlBr(), htmlSpan("Version"), htmlSpan(2)))

into this:

app$layout(list("My app", htmlBr(), "By Dean Attali", htmlBr(), "Version", 2))

[alexcjohnson]

See also: plotly/dash#1620