Now in NodeBB there are many useful things. I have a suggestion that will be useful to many. I'm ready to do it all himself. Requires only the consent of the developers.
To solve my problem requires two additional fields in category management page and template category:
meta description and
meta description field filled it will be inserted in the html tag template category, if not will be entered default field
content field will be used at the top of the template category, before the breadcrumbs and will contain anything: h1, image, description...
On the edit page, the category will be the area to edit the text of this field in the format markdown.
These fields are not mandatory and I will try to do so that they are compact and convenient location.