Change target for "How to install Julia and Pluto?"

[gdalle]

The "Edit or run this notebook" button is one of my favorite features of Pluto, since it contributes a great deal to ease of use and reproducibility.
At the moment, the link entitled "How to install Julia and Pluto?" points to the MIT course page https://computationalthinking.mit.edu/Spring21/installation/. Could we maybe replace this target with a page hosted by Pluto itself, which contributors could update as software versions evolve? It could be the exact same HTML for all I care, but the possibility to keep Julia and Pluto versions current would mean a lot to confused students.

[gdalle]

Would you be open to a PR on this? What form should it take, just a Markdown page?

[fonsp]

Hey @gdalle ! We are currently hard at work on our new website, so we will pick this up once done

[fonsp]

Also feel free to update https://github.com/mitmath/18S191/blob/Spring21/website/installation.md !