Feature Request: Quickstart: Add a book now button linking to /me/concierge on the purchases page

### What

Quickstart: Add a book now button linking to /me/concierge on the purchases page

### Why

When a user purchases a Quickstart session, they don't always book this straight away. The email that contains the link /me/concierge/ get's lost and user is unable to find out where to book the session.

The Quickstart session is available in the WordPress.com purchases page: https://wordpress.com/me/purchases > but the next steps to book that don't seem apparent.

Adding a booking button would help to lead users to book their sessions when they need to.

### How

For example:

Start at the WordPress.com purchases page implementation and review how Quickstart sessions are displayed. Trace the existing booking-related links and confirm the intended destination is /me/concierge. Done means a visible “Book now” button appears for a purchased Quickstart session and takes the user to that destination.

Written by the indexing model from the issue text.