Adding a subtitle on a shop page

Site URL: https://www.juliestamenic.com/printstore

Dear all!
Does anyone know how I could add a sentence under the Print Store title OR under the categories?
I'd just like to add "All photos are printed on luster paper, one of the highest quality papers on the market"

Thank you so much!!!

Add to Design > Custom CSS

h2.nested-category-title:after {
    content: "All photos are printed on luster paper, one of the highest quality papers on the market";
    display: block;
    font-size: 18px;
}