Solution is showing when entering into an exercise

[minimum-sauce]

Current behavior

Currently, entering into an exercise will show both the solution and the answer. This becomes a problem, especially for questions without any images, since part of the solution will because parts of the solution gets shown.

Expected behavior

Some form of separation between the question and the solution. Either by hiding the solution initially or having separate slide for the solution.

Proposed solution

From building the repo and testing out possible solutions, one way to solve this problem is by adding a:
``` {toggle}
:view:
solution
```
to each of the exercise solutions. This initially hides the text in the block.
I got this information from https://jupyterbook.org/en/stable/interactive/hiding.html.
testing it out on one of the questions give the following look:

[bonassifabio]

Thanks for pointing out the issue. I guess the best solution would be to use collapsable headers, but Jupyter Book does not seem to support them.

According to the Jupyter Book devs, using the {toggle} or {dropdown} directive breaks the compatibility with Jupyter Lab, which would defeat the purpose of the interactive book.

I'll leave the issue open, just in case someone has an idea on how to achieve this.