Original Question:

I have some categories for Layout Templates, Card Templates, Embellishment Templates, Paper Templates. I would like to reorganize the categories to be "Templates" at the top level and then move the individual template categories under it. How do I do it?

The categories in the Organize pane, work the same way as the file tree - click & drag!

So right click & choose New Category 'Templates' at top level.

Then click & drag each template subcategory into it.

Order of the categories:

The order of the categories are forced alphabetical.  If you wish to have a specific order of categories, rename the categories (right click and choose Rename) with 0_category name, etc.