Update account deletion strings to mention professional learning for …

[maddiedierker]

…teachers

This updates account deletion text that said "personal information, coursework, and projects" to "personal information, coursework, projects, and professional learning information" (for teachers only, since PD doesn't apply to students).

Examples

On /users/edit:

Upon clicking "delete account" (in DeleteAccountDialog):

[islemaster]

👍

[aoby]

Thanks for adding this text!