COSMOS example notebook

[raphaelshirley]

Closes #13

Basic example notebook running cosmos on a small number of objects that can be increased by the user

Problem & Solution Description (including issue #)

We will want to wait till latest Param changes are merged and rewrite before merging.

Code Quality

• [x] My code follows the code style of this project
• [x] I have written unit tests or justified all instances of #pragma: no cover; in the case of a bugfix, a new test that breaks as a result of the bug has been added
• [x] My code contains relevant comments and necessary documentation for future maintainers; the change is reflected in applicable demos/tutorials (with output cleared!) and added/updated docstrings use the NumPy docstring format
• [x] Any breaking changes, described above, are accompanied by backwards compatibility and deprecation warnings

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 7.14286% with 13 lines in your changes are missing coverage. Please review.

Project coverage is 46.57%. Comparing base (14a5c3b) to head (dca196e).

Files	Patch %	Lines
src/rail/estimation/algos/lephare.py	7.14%	13 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #42 +/- ## ========================================== - Coverage 49.63% 46.57% -3.06% ========================================== Files 2 2 Lines 137 146 +9 ========================================== Hits 68 68 - Misses 69 78 +9 ```

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