[UX] Decrease size of help text input textareas

Describe your issue or idea

All the "help text" textfields are huge. Can we please limit these to textfields instead of text areas?

To see an example of this part of the admin interface, use the admin menu to navigate to: Structure → Content types → Page → Manage fields → Body → Edit. Here's what it looks like:

Current Proposal (as of Sept 29, 2020)

Reduce the size of the text area.