[Feature Request] provide template for field content as [html:template-xy.html] - similar to [sound:xyz.mp3]

Please provide a mechanism to drop a text file into an anki field.
This text file contains the content of an anki field that can be used for this card and other anki cards.
The mechanism should then save the file into the same folder where sounds and images are stored.
The mechanism should also create a tag within the field.
Whenever this tag is used in a field, the content of the template file should be rendered into the tag.
This way, users could create a template that can be reused for many cards.
It is also possible, to change content on the template for many cards.
This is saving a lot of time for creating questions on same content.
instead of

Why not use card templates?

This would be a lot of card templates and its not as flexible.