In all Magento 2 courses and tutorials recommended to create vendor and then theme in the /app/design/frontend/VENDORNAME/THEMENAME
.
http://devdocs.magento.com/guides/v2.1/frontend-dev-guide/themes/theme-create.html for example.
But luma and blank theme are located in /vendors/magento/theme-frontend-luma
and /vendors/magento/theme-frontend-blank
.
Should and may we place theme in vendors?
When and why we should do so?
If I place new theme it will not be added to DB. Is there any installation procedure, that differs from creation in /app/design/frontend/
?