I've looked at every language file to change the user registration email and cannot seem to find it. It should be in the en-GB_com_users file, but it isn't.

This is what the current email sent to users after registration looks like:

Hello [name],

Thank you for registering at [sitename].

You may now log in to [siteurl] using the following username and password:

Username: [username]
Password: [password]

Any idea of which file I could find the language for this email to edit?

Thank you!