#60 Add image viewer.

[Illia-M]

Add fancybox for image preview - very nice library.
When download folder - try use name of folder as archive name.

[qoomon]

N1. Could you merge master branch, because I already implemented the download archive naming.

[qoomon]

Would be nice to display markdown preview alike to images. maybe load markdown in an iframe could be a simple solution

[Illia-M]

1. in my case folder name contains Ukrainian chars and was url encoded so I need decodeURIComponent for name before use it in file name. I try catch errors if some how name extraction failed.
2. I think a lot about markdown files, separate tab it's useful for some cases but in my it will be nice display in same table view if only one md file inside folder, maybe only for some name.

But for this PR I want only merge image preview)
Thank you for refactoring, I'm not familiar with JS stack. Editorsconfig would be great help to met rules.

Can we merge it? Folder naming can be here, separate PR or I can leave it for my fork

[Illia-M]

I want update and fine-tune this lib

[qoomon]

maybe I'll go fore https://github.com/VueFilesPreview/vue-files-preview in a future release. WDYT

[qoomon]

Let's wait for VueFilesPreview/vue-files-preview#16