Missing download button for pdfs in tutorial section

[christian-rli]

This was requested within a discussion of the oefamily developers.

[wingechr]

I see 2 possible ways:

• using some mkdocs plugin like https://github.com/zhaoterryy/mkdocs-pdf-export-plugin to create pdfs for all pages every time the site is updated

• just trigger the browsers window.print javascript to print current page to pdf on damend

[wingechr]

I think I would prefer the second because I feel this is rather limited use case and creating all those pdfs on every update seems like a lot of unnecessary work for us and the github server