Splito tutorials and docs

[zhu0619]

Changelogs

• [ ] Tutorials in docs/tutorials/*.ipynb

• [ ] Create documentations with mkdocs

Checklist:

• [ ] Was this PR discussed in an issue? It is recommended to first discuss a new feature into a GitHub issue before opening a PR.
• [ ] Add tests to cover the fixed bug(s) or the newly introduced feature(s) (if appropriate).
• [ ] Update the API documentation if a new function is added, or an existing one is deleted.
• [ ] Write concise and explanatory changelogs above.
• [ ] If possible, assign one of the following labels to the PR: feature, fix or test (or ask a maintainer to do it for you).

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discussion related to that PR

[hadim]

@zhu0619 I did some tweaks.

Overall, I am fine merging here, and thanks for the tutos.

Some would probably deserve a bit more text with context and explanations, but this is something we can also tackle later. The minimal is here and gives a good overview of the API to the users already.