Update Site Profiler "Migrate site" button link and text

[inaikem]

What

Update the Site Profiler's heading information "Migrate site" button text and link.

  Currently:

Why

• To help attract more users to our Happiness-assisted migration service.
• To reduce usage of Move to WP.com (see pdqkMK-1db-p2)

How

Update the button text: "Get a free assisted website migration"

  Update the link: https://wordpress.com/setup/new-hosted-site/plans?ref=site-profiler&section=heading-information

Note: I have updated the referrer link to reflect the same information being shown on https://wordpress.com/hosting

  Visual example:

Cc: @bohdankit07

[mrfoxtalbot]

Moving to "Done" and marking as triaged.