Add links to hackaburg 2016 + 2017 websites

[xam-ps]

Is your feature request related to a problem? Please describe.
Eventually we want to have the full hackaburg website history back online

Describe the solution you'd like
Websites from 2016 and 2017 have be rebuilt and linked

Describe alternatives you've considered
If this is too much work, we just don't do it

Additional context

[phntxx]

The two sites in question are Hackaburg 2016 and Hackaburg 2017, both varying in difficulty regarding a rebuild:

The Hackaburg 2017 website source code is available here and should be easy to rebuild, as it should only require configuration changes and maybe the usage of legacy tools to create a build.

The Hackaburg 2016 website wasn't written by us, but rather created using a website generator. This introduces the difficulty that the code cannot simply be reused (a lot of SplashThat sources intermingled with website design), but rather needs to be completely recreated (preferrably as detailed as possible). Legally this might also not be a good idea, but there's reasons as to why I'm not a lawyer.