Update tutorial and examples

[DouglasMesquita]

Link to the Issue

close #104

Definition of Done

For each one of the examples/tutorials:

• Use app <- AppDriver$new only once
• Call app$close at the end of the code
• Force the installation of the newer shiny version using renv::install

How to test changes

Follow tutorial instructions and be sure it works if you follow correctly the steps

Tasks for PR author

• [x] Test your change and ensure there is no regression
• [x] Change has a corresponding issue. Ensure it is linked in GitHub
• [x] Author of the change opened a pull request and assigned a reviewer

General policy:

• If applicable - add instructions for testing
• If there’s no issue, create it. Each issue needs to be well defined and described.
• All interaction with a user, user-facing messages, plots, reports etc. are written from the perspective of the person using or receiving it. They are understandable and helpful to this person. If a user sees an error message, there is a call to action, i.e. the user knows what to do to fix it.
• README, other documentation and code comments that we have is updated with all information related to the change.
• All code has been peer-reviewed before merging into any main branch
• All changes have been merged into the main branch we use for development.
• Continuous integration checks (linter, unit tests, integration tests) are configured and pass.
• Optional: unit tests added for all new or changed logic.
• All task requirements satisfied. If not describe it here. The reviewer is responsible to verify each aspect of the task.
• Change covers only things in task. Please create new PR if you want to fix something else.