Adds Jira to GitLab tutorials

What does this MR do and why?

Adds a Jira migration options page to the Import and Migrate > Jira section to explain all of the options a user has to migrate project from Jira into GitLab.

This was originally written as a tutorial, but the tech writing team felt this might be better as a standalone topic in the new location (near the Jira issue importer doc) instead.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After
	https://main-ee-156935.docs.gitlab-review.app/ee/user/project/import/jira_migration_options.html

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.