added router to /solution where the solution is displayed not yet formatted as text + using express instead of http directly

added router to /solution where the solution is displayed not yet formatted as text + using express instead of http directly

+headline +select for difficulty but not working yet +spacing in between elements is not better + added difficulty selector but for now only in vscode possible to change nb of zeros

did not manage to include self made solver in python in js project using pycharm. Now using aquivalent from chatgpt in js