Code Insights: Add template section to the getting started page

Created by: vovakulikov

Closes https://github.com/sourcegraph/sourcegraph/issues/30158

Context

Designs

This PR just adds the template section component to the getting started page. Also in these PR changes, you can find a static non UI file where all templates for code insights and this section are stored. If you want to add/delete/edit a template for this section this is your file to edit.

For reviewers

@oleggromov I had to slightly extend the <Tab /> component in the wildcard in order to add custom styles.