View story description as modal or as side content

https://ombulabs.atlassian.net/browse/DT-258

**Branch/Commit:**

Main branch.

**Describe the feature:**

As a user, I want to be able to click a story and read its description without having to open it in a new tab and without changing the page to a new page so I can close it and keep reading other stories.

**Problem:**

Currently, reading stories of a project requires you to open it in a new tab or change pages and then go back with the browser history. A workaround is to click `add estimate` and the story opens as a modal.

**I will abide by the [code of conduct](https://github.com/fastruby/points/blob/main/CODE_OF_CONDUCT.md)**

Start from the project’s story list and the existing “add estimate” modal behavior described in the issue. Trace how a story currently opens, then make the story description available as modal or side content without navigation; done means it opens from the current page and can be closed while continuing to read other stories.

Written by the indexing model from the issue text.