Delta Sync on Sync Gateway

https://docs.google.com/document/d/1SG0-eRA8qSMPBNnROGTnwYMebNJOJIe1Eq4GtVkX8wE/edit#heading=h.7as5wmsq8ek4

Tasks:

• [x] Include delta sync config in Getting Started journey for better visibility
• [x] Link to reference property from the Getting Started for more information
• getting started config now exists in two variants (without the import filter and with).
  • [ ] update the import filter config with the delta_sync object and callout.
  • [ ] update getting-started.adoc with the same description as for the non-import filter tab