Update wording in the tutorials

[psteinb]

While I was working through the tutorial (which are great!), I took the liberty of refining some wording. I very few mistakes of English language. I also added some bits here and there to make the tutorials more readable (for someone like me). I hope you find this useful.

[psteinb]

Note, I used nbterm to edit the notebooks. Notebooks are not great for diffing and creating PRs in general when opened with jupyter. In any case, I observed that nbterm replaced some characters with unicode equivalents. Whoever reviews this PR, please have a look at the notebooks locally first. They view fine on my box, but you never know.

[francois-rozet]

Hello @psteinb, thanks for the feedback and fixes! I agree with most of your additions but made a few wording suggestions.

I still have to check that the UTF-8 edits display correctly in the docs and locally.

[psteinb]

Just saw that this is merged. Thanks so much for the trust. And sorry for not replying to your question here. Is this still an open issue?

[francois-rozet]

No problem, thank you for the edits, I think the tutorial is much clearer now!

Is this still an open issue?

I think its fine like it is now. Feel free to open another PR if you want to improve the tutorials (or add new ones), though!