Zeta Ssp Bid Adapter: Update adapter docs (#2989)

* docs update for eids object

* fixes by review

* other docs changes

* minor fix: all userIds

Co-authored-by: Surovenko Alexey <surovenko.alexey@gmail.com>

dev-docs/bidders/zeta_global_ssp.md

@@ -7,6 +7,10 @@ biddercode: zeta_global_ssp
 bidder_supports_deals: false
 media_types: banner
 gdpr_supported: true
+usp_supported: true
+coppa_supported: true
+userIds: all
+prebid_member: true
 gvl_id: 833
 ---
 
@@ -20,9 +24,10 @@ All references to the OpenRTB spec refer to OpenRtb v2.5 (https://www.iab.com/wp
 {: .table .table-bordered .table-striped }
 | Name                 | Scope    | Description                                                                                                         | Example      | Type      |
 |----------------------|----------|---------------------------------------------------------------------------------------------------------------------|--------------|-----------|
-| `user`               | required | The object containing user data (See OpenRTB spec)                                                                  | `user: {}`   | `object`  |
-| `user.buyeruid`      | required | Zeta's user id                                                                                                      | `"12345"`    | `string`  |
+| `user`               | optional | The object containing user data (See OpenRTB spec)                                                                  | `user: {}`   | `object`  |
+| `user.buyeruid`      | optional | Zeta's user id                                                                                                      | `"12345"`    | `string`  |
 | `tags`               | optional | The object containing set of  Zeta's custom tags witch publisher have to supply                                     | `tags: {}`   | `object`  |
 | `site`               | optional | The object containing site data (See OpenRTB spec)                                                                  | `site: {}`   | `object`  |
 | `app`                | optional | The object containing app data (See OpenRTB spec)                                                                   | `app: {}`    | `object`  |
+| `sid`                | optional | Seller ID. The identifier associated with the seller or reseller account within the advertising system              | `"1q2w3e"`   | `string`  |
 | `test`               | optional | Flag which will induce a sample bid response when true; only set to true for testing purposes (1 = true, 0 = false) | `1`          | `integer` |