Upgrade front-end framework

[fsimonis]

Our front-end is using Bootstrap 3.3.7 with custom CCS for some styling customization.

This version was released in July 2016 and is pretty much ancient.

We need to upgrade to a modern CSS front end, however, it doesn't need to be Bootstrap again.

What's important for us is:

• We are no web devs and need something simple to setup and simple to use, something that works pretty much out of the box.
• We at least need to modify default colors.
• Direct support for nested expandable menus is a big plus.
• We should pick something that integrates well with static site generators, now jekyll and later hugo.

[Harsh22428]

Hi @fsimonis
I want to work on this issue to improve the frontend.
please assign this issue.

[MakisH]

@Harsh22428 If you found this repository in the context of the GSoC, please note the application procedure and guidelines in our GSoC page.

In that context, this is one of the core issues of the "website modernization" project, which is meant to take place in the summer.

[aayushi-singhhh]

Hi @MakisH @fsimonis can I work on this issue? I have already sent my introduction on the discussion forum.

[MuhammadAashirAslam]

We have decided to move to the latest version of the Bootstrap - 5.3.8 . The work is currently done in the PR #922 . Suggestions and improvements are welcomed!