add white background to the thumbnail images and an orange border while mouse hovers

[Dbest2018]

[Niklas-dev]

I would like to work on this issue, could you provide some more informations?

[Dbest2018]

if you take a look at the screenshot in the README file, you would see a section of the page that has two section of the images, in the first section the image is large, while the second section has a list of five images, when any of the images is clicked in the list is the it shows the image in the large section, each image clicked should change the background to white and an orange border to show that it has been selected