Update mkdocs.yml

## Changelogs - Add tutorial to mkdocs file. --- _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)._ --- _discussion related to that PR_