Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

Currently the <RichText /> component allows for for the user to enter multiple lines.
It would be great if there was a way to limit the that.
This would allow for blocks to be build that would allows the user the user to enter rich text but only in a single line.

The current usecase for that is the following Contact Info component that I am building.

I want to be able to let the user bold or italicize part of the address for example.

Describe the solution you'd like
Allow us to pass multiple={false} as a paramter to richtext.

Describe alternatives you've considered
The current solution that doesn't quite work as expected that I got working is to use

<RichText 
    unstableOnSplit={ () => false } 
/>