Add table/section on the scientific usecases to the READMEs

[elboyran]

• [x] Mention scientific tutorials in the key-points of dianna
• [x] Update README on tutorials and data/explainer plans
• [x] A separate table in the main README with these tutorials
• [x] Paragraph/separate section/table about these tutorials in the tutorials README
• [x] Improve the hyperparameter values tables with a one-liner explanation of the expected effect of changing each parameter. For instance for 'n_mask': "Higher values increase stability at the cost of computation time." as suggested by @cwmeijer in PR #737.

[elboyran]

Adding things to the README should be balanced as removing things from there. I suggest the Getting started to be largely moved to the (new?) demo notebook. To be combined with the #732.

[elboyran]

@cwmeijer if you know about more expected effects from changing the hyperparameters than given in WIllem's thesis and the related PR, please, add them in the Tutorial's README extension.