Splines

This shouldn't be a problem anymore with the reworked strategy of the user cleaner in #647.

Hey @zebleck, I've seen that you worked on the first version for better user management [here](https://github.com/MaMpf-HD/mampf/commits/better-usermanagement). Would it be possible for you to maybe open a PR for this explaining...

@fosterfarrell9 Could you create a list with the most important items (according to your opinion) that should definitely be in such a wizard for creating a new medium? Maybe you...

In #628, we've improved the UX for the administration of a lecture in the role of a teacher of lecture editor. Instead of a wizard, we've split the components into...

We should consider #421 alongside this.

Also consider the role of the `sprockets` asset packing library along the way and its interplay with webpacker. This already feels like it's going to be a big pain to...

We should also consider the bug https://github.com/MaMpf-HD/mampf/pull/468. Maybe, we can manage `.css` files, so they are really only applied to the partials etc. and not mingled together into one big...

@fosterfarrell9 Ok true, that might really be challenging, especially for all the already existing files. So, it'd be probably easier to continue using explicit CSS, e.g. `#my-super-cool-div-wrapping-things .li { ......

The only thing missing right now is HTML file linting (including ERB support). And also CSS linting. And migration from CoffeeScript to JavaScript.

~~Note: Also try to switch to another datetimepicker or import it in a more canonical way instead of the dirty and fragile hacks in `application.js`.~~ Fixed in #526