Allow totp from Heroku to be suggested where it is validated

[louim]

Overall Checklist

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

for shared-credentials.json

• [x] 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.

Hello! This is my attempt to fix https://github.com/apple/password-manager-resources/issues/695

Heroku uses verify.salesforce.com for TOTP validation. If I understood the file syntax correctly, this change would allow password managers to suggest TOTP from Heroku credentials when the user is on verify.salesforce.com.

[rmondello]

Thanks @louim!