Add "Warning" and "Tip" settings to custom fields

[mmikkel]

It'd be great if it was possible to add warning and tip texts to custom fields, in addition to the basic instruction text.

To be clear; here are the tip and warning texts I'm referring to (the basic instruction would render below the label and above the field; the tip and warnings render below the field):

(I realise that there are UI elements for tips and warnings, but IMO field-specific warnings and tips still have merit.)

[mmikkel]

I'm not sure if these settings should be "Default Warning" and "Default Tip", and possible to "relabel" in field layouts (i.e. similar to the "Default Instructions"). Possibly yes, due to consistency if nothing else?

[brandonkelly]

Yeah, probably, along with “Hide” checkboxes in case you want to explicitly remove the default tip in some cases.

[mmikkel]

Added in 5.4.0 (#15632 (comment)) 🎉