Add shared credentials for Performable (performable.com → hubspot.com)

[mangeshraut712]

Bar check: This meets the shared-credentials bar. Performable and HubSpot are the same product. www.performable.com/login redirects to app.hubspot.com/login, which returns 200 with the title HubSpot Login and Sign in, and a nonexistent path on that host returns 404. A password saved on performable.com is the password for that same account on hubspot.com.

The old apex redirects to the HubSpot site, so performable.com is marked obsolete.

Evidence, checked live:

• https://www.performable.com/login → 301 https://www.hubspot.com/login → 301 https://login.hubspot.com/login/ → 302 https://app.hubspot.com/login/ → 200, title HubSpot Login and Sign in. The initial HTML has no type="password" input.
• https://app.hubspot.com/login/ → 200 with the same title.
• https://app.hubspot.com/this-path-should-not-exist-4a36 → 404, title HubSpot Error
• https://performable.com/ → 301 https://www.hubspot.com/ (title HubSpot | Software & Tools for your Business - Homepage)

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 shared-credentials.json

• There's evidence the domains are currently related (www.performable.com/login redirects to the HubSpot login)
• If using from and to, the from domain redirects to the to domain to log in