I am not aware if this feature is included in the latest jekyll release. A little while ago I created my own solution for this. You can take a look at my theme: classic-jekyll-theme to see how I did it exactly.
The short of it is: create a layout that generates the page, and then create ‘pseudo’ pages to trigger the generation process.
These pseudo pages only need to contain some yaml like:
This would create a page of all posts in the "classic’ category.
For the generation of the page itself, please take a look at the theme.
No. Please take a look at my theme. The following information applies to the CLASSIC-JEKYLL-THEME only! (I.e. not to the default Jekyll theme ‘minima’)!!
In the _layouts folder there is a file called category-page.html
This file creates a category page of all posts that refer to a category.
To trigger the generation of a category page you need another file (for example in a pages directory) that specifies the layout generator category-page and specifies for which category it should generate a page. The yaml title is used for the category page.
Please keep in mind that you need my Classic-Jekyll-Theme for this to work.
The reason why I am posting this to point you to an example that can generate category pages. But you will still have to write the generator yourself. Or use my theme