WithField(fieldName) should assign the fieldName as the display name by default.

[MikeAlhayek]

Is your feature request related to a problem? Please describe.

If we have the following migration

_contentDefinitionManager.AlterPartDefinition("CustomPartName", part => part
    .WithField("Description", part => part
        .OfType("TextField")
        .WithEditor("TextArea")
    )
    .WithField("Info", part => part
        .OfType("TextField")
        .WithEditor("TextArea")
    )
    .Attachable()
);

There will be two fields added to the CustomPartName. The display name of both fields will be "TextField". I think by default, we should name then the "Description" and "Info" names unless the user uses WithDisplayName("Other Description") to change it.