Add Magnific Popup to the style

[fmaussion]

While writing this blog post I was really keen on getting the same functionality as in my website : clicking on an image allows to navigate between all images in the same post.

I found out that my jekyll template is using Magnific Popup to do the job. I tried to add it to our jekyll template but my css / jekyll skills are way too low for this.

[fmaussion]

My jekyll template has it: https://github.com/fmaussion/fmaussion.github.io/search?q=magnific&unscoped_q=magnific
... but the OGGM template does not.

[fmaussion]

Closed via #75