install problem, no layout folder

[zzw0034]

HI,
i am a new user for wowchemy. I am trying to add a image gallery with your method. But the first strop to install Hugo-easy-gallery,

Put files in following places:
/layouts/shortcodes/figure.html
/layouts/shortcodes/gallery.html
/layouts/shortcodes/load-photoswipe.html

I cannot find there is a layouts folder for wowchemy https://github.com/wowchemy/starter-hugo-research-group.
Could you help to understand and use the Hugo-easy-gallery

thank you!