[com_fields] Improving Custom Fields - Tooltip for the Field "Description"

[coolcat-creations]

The tooltip for the description doesn´t tell the User really what happens with this input.
I´d rather say here it´s "The description which will appear in a tooltip when a user hovers the label".

If someone tells me this sentence in clean english i can make a PR.

How about "A description of the field which will appear in the label tooltip"

[zero-24]

PR #13557