[hungvu193]

For https://github.com/Expensify/Expensify/issues/686749

Documents the new expensifyCard create job in the Integrations API, which issues a virtual Expensify Card to an existing employee:

1. Request example, success response and error example.
2. Who can call it, the requirement that the employee already exists, and retries with externalID.
3. inputSettings and personalDetails tables, the rule for details already on file, and the error codes.

The generated index.html ships in the Integration-Server PR.