feat: add schibstedmarketplaces -> vend

[Johannes-Andersen]

Ref announcement https://vend.com/news/schibsted-marketplaces-becomes-vend-a-new-name-for-a-smarter-future

Overall Checklist

• I agree to the project's Developer Certificate of Origin
• The top-level JSON objects are sorted alphabetically
• There are no open pull requests for the same update

for change-password-URLs.json

• There is no Well-Known URL for Changing Passwords (https://example.com/.well-known/change-password)
• The URL either makes the experience better or no worse than being directed to just the domain in a non-logged-in state

for shared-credentials.json

• There's evidence the domains are currently related (SSL certificates, DNS entries, valid links between sites, legal documents etc.)
• If using shared, the new group serves login pages on each of the included domains, and those login pages accept accounts from the others. (For example, we wouldn't use a shared association from google.co.il to google.com, because google.co.il redirects to accounts.google.com for sign in.)
• If using from and to, the new group, the from domain(s) redirect to the to domain to log in.