Implement GitBook-like documentation

[jonathan-mayer]

Issue

Currently there isn't a whole lot of documentation on actually using the downscaler, additionally it can be overwhelming seeing the large README. Instead we should consider adding something like a GitBook (probably something more like Docusaurus since it is free for everyone, not just individuals).

Further details

This is a pretty large project, which will probably not be implemented in the near future.

Proposal

We should evaluate if we actually want/need this, when we should implement it, think about the things we would document in there and how it would be structured.

Who can address the issue

Other links/references

[jonathan-mayer]

https://docusaurus.io/docs/deployment#deploying-to-github-pages
https://docusaurus.io/docs/installation

[jonathan-mayer]

I made the basic structure on feat/add-docusaurus
* the HomepageFeatures have to be adjusted, and there is currently no content on any of the sites

[jonathan-mayer]

the implementation in feat/add-docusaurus is ready for content.

TODO:

• fill out about page
• add documentation about:
  • cli arguments
  • helm chart
  • troubleshooting (possibly in guides)
  • annotations
  • layers
  • values
  • anything else from readmes
  • repo management ( e.g. steps to releasing a new version, updating docs, ...)
  • ...
• add guides about:
  • basic operation
  • migrating from py-kube-downscaler (detailed)
  • developing (downscaler, website, helm chart)
  • ...
• Optional: add more to homepage
• simplify readme
  • link to documenation
  • explain where to add and update documentation (website/content/docs or website/content/guides) (probably in docs on website)
  • remove documentation from readme (i would keep e.g. developing)
  • add testing/running the website to developing

* if you have any more ideas for content write them in here or open an issue (if this one is already closed)