Add AnnotationSeries example to intro tutorial

[ehennestad]

Motivation

Add example of AnnotationSeries to tutorials

How to test the behavior?

run intro.mlx

Checklist

• [x] Have you ensured the PR description clearly describes the problem and solutions?
• [x] Have you checked to ensure that there aren't other open or previously closed Pull Requests for the same change?
• [x] If this PR fixes an issue, is the first line of the PR description fix #XX where XX is the issue number?

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 90.80%. Comparing base (d970ef1) to head (baca72a). Report is 1 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #622 +/- ## ======================================= Coverage 90.80% 90.80% ======================================= Files 107 107 Lines 4774 4774 ======================================= Hits 4335 4335 Misses 439 439 ```

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