If you are using the latest email template module from app store then these settings have changed and I think they are not updated in the documentation link you have provided above.
If you goto email template module >> USE_ME>> Functional >> Snippets >> Administration you will find the overview snippet that contains all the email configurations. You need to create a new page for example called email overview and use the snippet call and add the Administration snippet and then attach that page to your navigation. (see the snapshot below)
To give security access rights goto project security (first module in your project) >> open Security >> Goto user roles tab >> Edit Administrator role >> edit module roles >> and give access rights to Email template module (see screenshot 2 below)
Also read the HOW-TO's for creating a secure app to get better understanding on app security.
Hope this helps!
I guess they've changed the email module somewhat since that instruction was written. To the best of my knowledge, everything (including templates) are now managed from the snippet 'administration' in the USE_ME folder.
You're probably better of reading the instructions for the module in the appstore. Those should be up to date.
Notice that the "how-to" is dated from 2014, so it could be that MF isn't there anymore. The overviewpage though is still there as Emailtemplate.EmailtemplateSoverview (search on emailtemplatesoverview after you have add the module in the modeler)
Furthermore to access the emailtempaltesoverview page, add a menu item in navigation with emailtemplatesoverview as target and you can access your emailtemplates overview (dont forget to set up your module roles, user roles).