Moves all solutions to notebook files for easier copy-pasting.
Reviewer tip: copy old .txt solution files to external folder, then open new solution .ipynb files and copy-paste old solutions into them. There should be no difference. (automatic diff tools are difficult to use here because the ipynb files are fomatted as json).
Moves all solutions to notebook files for easier copy-pasting.
Reviewer tip: copy old .txt solution files to external folder, then open new solution .ipynb files and copy-paste old solutions into them. There should be no difference. (automatic diff tools are difficult to use here because the ipynb files are fomatted as json).
Closes #112