Need to fix variables

src/registrar/templates/emails/domain_invitation.txt

@@ -1,11 +1,9 @@
 {% autoescape off %}{# In a text file, we don't want to have HTML entities escaped #}
-Hi $CONFIRM_firstname.
+Hi {{ incoming-email-here }}.
-{{ contact.first_name }}
+# We don't know their first name until they make an account, we only know their email
+# Stuck here because we only get their email from the form, so can't pull above?
 
-
+{{ contact-of-whoever-owns-usually-admin-or-maybe-security-contact }} has added you as a manager on {{ domain.name }}.
-$CONFIRM_name-of-person-who-added-this-person has added you as a manager on {{ domain.name }}.
-{{ application.submitter.first_name }}
-{{ application.submitter.creator }}
 
 YOU NEED A LOGIN.GOV ACCOUNT
 You’ll need a Login.gov account to manage your .gov domain. Login.gov provides a simple and secure process for signing into many government services with one account. If you don’t already have one, follow these steps to create your Login.gov account <https://login.gov/help/get-started/create-your-account/>. 

src/registrar/views/domain.py

@@ -338,6 +338,8 @@ class DomainAddUserView(DomainPermissionView, FormMixin):
                     context={
                         "domain_url": self._domain_abs_url(),
                         "domain": self.object,
+                        # "user": the original person or contact
+                        # "email": email of person we want to add
                     },
                 )
             except EmailSendingError: