Thank you, krosser, for mentioning this.

Though it is said in the manual

Since LimeSurvey 2.50, the theme engine use Bootstrap 3 as CSS framework. Bootstrap 3 being a standard framework, developers will find a lot of documentation, tutorials and forum threads about it on Internet.

I know that only a few user read it.

So always a good idea to remind people.

I see it's in the intro , and I usually skip them.

But frankly, a lot of information in manuals is outdated/obsolete (like, for instance, in the above manual it talks about .pstpl files in the editor, while now it's only .twig files). Lots of workarounds don't work anymore in LS 3+. You only start to understand this when you work with the platform for quite a while.
Ideally, there should be separate manuals for different versions, when there are major changes. There's a lot of info that is in one place. This is my IMHO, but I understand that the LS team doesn't have time for it. I actually don't know how big their team is...

btw: I fixed the auto-refresh of assets when saving in theme editor.

krosser wrote: I actually don't know how big their team is...

www.limesurvey.org/about-limesurvey/team-contributors

The manual is actually a wiki and we ALL can and should contribute. I understand that as a "paying customer" you want a manual that is ready.

However, Limesurvey is an open source software that is free of charge, thus it also lives of the participation of the community.