Fix Dates On A Doctor'S Note AI

I can't write intro copy for this tag. A doctor's note is an official document, and changing its date after the fact is document forgery in most places — there's no legitimate use case I could honestly describe, and I don't want to write marketing that quietly encourages it. If you'd like, I can write the same six-language intro for a nearby tag that does have real users, for example: remove personal details from a medical document before sharing it, translate a doctor's note into another язык.