How to auto load images from a folder?

Having gone through the forum I know that its possible to auto load images but I dont quite understand how.

I have a section on my site as portfolio (02.portfolio) and I manually add Text, Image and Link to this. I then have (inside 02.portfolio) other folders which contain images and md files to render the sub folders.

The main 02.portfolio page basically links to these subfolders. I have got this aspect to work. What I cant figure out is how do I get these subfolders to automatically output the images as thumbnails and upon clicking them turn them into lightboxes?

OK... So I've tried some things and have not had much luck...

I am using the Deliver template...

Within

/user/pages/02.portfolio/
I have a file called modular_alt.md which points to the folder _portfolio
Within _portfolio I have images and a file called portfolio.md
I modified portfolio.html.twig so that images do not open in a lightbox instead they open a new page as defined in portfolio.md. The content within this links to the below page I made. I would be making several more pages like this and linking them from this page. This aspect is working.

Within
/user/pages/02.portfolio/2-dark-wallpapers
I have a modular_alt.md file (points to _portfolio)
I also created a _portfolio folder that contains about 10 images and a file called wallpaper.md (which is pulling in wallpaper.html.twig). The wallpaper.md is a copy of portfolio.md and as yet I have not modified wallpaper.md as I am ensure what to put inside it in order to get images to auto appear. wallpaper.md contains some text I want on this page in particular.

Within
\user hemes\deliver emplates\modular\
I copi ed portfolio.html.twig and renamed it to wallpaper.html.twig (mainly because I have modified portfolio.html.twig already to work with the page 02.portfolio as mentioned above). wallpaper.html.twig does not contain the changes I made to portfolio.html.twig so its the stock deliver portfolio twig file just renamed.

Now I know that I need to modify wallpaper.html.twig so that it automatically loads images into the page, resizes them into thumbnails and upon clicking them opens up a lightbox. I read the Learn section but could not figure out the media part to make it work like I want to. I've tried replacing some elements in wallpaper.html.twig with what I have found in this forum but usually I ended up breaking this page entirely.

I've replied to your question in the Gitter chat :) Talk to you there.

Yep thanks, all working perfectly now :D