How should I structure my content?

I have a small publishing company, and I store my book catalogue as a Zenkit collection. I was wondering how should I port my content to Squidex using the Onix 3.0 XSD Schema from Editeur. When I paste the schema in Squidex, it doesn’t recognize it. Is it expecting a JSON schema ?

Link to the Schema:

I would be very helpful if anyone could point me in the right direction.

My Zenkit collection has the following structure:

Author Links to another Zenkit collection
Cover - JPG
Language - Tag
number of Pages - Number Field
Width - Number Field
Height - Number Field
Type of Paper - Links to another Zenkit collection
Book Spine - it’s a number value in milimiters as a result of a calculation / formula that uses height, width, # pages and a field from the Type of Paper collection item.
Category - Tag
Topics - Tag
Classification - Tag
Description - Text Field (600-800 chars long)
Recommended Titles - Links to other titles
Series - Text Field
Contained in - Subitem Container (denotes hierarchy below linked titles)
Recommended in - Shows what other titles are recommending this title
Laminate - tag
Book Flap - Tag
Text State - Tag
Cover State - Tag
Editor - Tag
Index - Text (contains lines of headers marked as H1 inside the book)
Weigth - Calculation / Formula (multiplies number of pages and paper weight)
DDC - Tags with hierarchy
IBIC - Tags with hierarchy

Sample Data