Update nuxt.js and documentation build mode
Desired behavior
Switch documentation builds to the newer Nuxt.js target: static flag. We'll need to do some study - see this post on StackOverflow.
Current behavior
We currently use the deprecated Nuxt.js mode: universal flag.
The Value Add
We will be up-to-date.
Related #197
This will require an update to nuxt.js and probably many other dependencies.
In the course of this update, worth looking at our outstanding security update notifications:
https://github.com/learningequality/kolibri-design-system/security
@AlexVelezLl noted that this may be blocked by and/or related to #439 -- possibly will be solved alongside that issue naturally.
This also impacts the work on KDS visual testing (the issue of upgrading Node, that is)