ci: add route maps

What does this MR do?

This adds a Route Maps in order for the View app link to point to the modified component's story in the Review app, similar to what we have in design.gitlab.com: https://gitlab.com/gitlab-org/gitlab-services/design.gitlab.com/-/blob/master/.gitlab/route-map.yml

Limitations

• This only matches components that are 1 level deep in the files structure (e.g. src/components/base/modal, but not src/components/form/form_input).
• Directory names that contain underscores are omitted because underscores are converted to dashes in the path parameter.

How to test this?

• Branch off this branch.
• Change some components.
• Push your changes and open an MR.

Here is an MR that showcases this where the View app dropdown should link to GlModal and GlDropdown stories: !1577 (closed)

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines.
• GitLab UI's contributing guidlines.
• [-] If it changes a Pajamas-compliant component's look & feel, the MR has been reviewed by a UX designer.
• [-] If it changes GitLab UI's documentation guidelines, the MR has been reviewed by a Technical Writer.
• [-] If the MR changes a component's API, integration MR(s) have been opened in the following projects to ensure that the @gitlab/ui package can be upgraded quickly after the changes are released:
  • GitLab: mr_url
  • Customers Portal: mr_url
  • Status Page: mr_url
• [-] Added the ~"component:*" label(s) if applicable.