Add initial documentation for Synapse HX adapter

Author: prebid-compas

dev-docs/bidders/synapsehx.md

@@ -0,0 +1,43 @@
+---
+layout: bidder
+title: Synapse HX
+biddercode: synapseHX
+description: Prebid Synapse HX Adapter
+tcfeu_supported: false
+coppa_supported: true
+gpp_supported: false
+floors_supported: true
+media_types: banner, video
+multiformat_supported: will-bid-on-any
+safeframes_ok: false
+schain_supported: false
+usp_supported: true
+pbjs: false
+pbs: true
+prebid_member: false
+fpd_supported: false
+privacy_sandbox: no
+ortb_blocking_supported: true
+sidebarType: 1
+---
+
+## Before You Begin
+
+The Synapse HX bidder adapter requires additional setup and approval from the Compas team. For additional information, please reach out to <prebid@compas-inc.com>.
+
+## Bid Params
+
+{: .table .table-bordered .table-striped }
+
+| Name | Scope | Description | Example | Type |
+| --- | --- | --- | --- | --- |
+| `tenantId` | required | Synapse HX tenant identifier | `'deadbeef-cafe-4bad-8000-feedfacecafe'` | `string` |
+| `adUnitId` | optional | Synapse HX ad unit identifier | `'cafebabe-feed-4f00-9000-deadbeefbabe'` | `string` |
+
+## Additional Notes
+
+### Request Attributes
+
+- Bids are returned in **net** - that is, the bids returned reflect the bid amount with revenue sharing already taken into account. No adjustment is necessary.
+- Ensure that the `tenantId` parameter is set correctly for your integration.
+- If the `adUnitId` parameter is omitted, the integration falls back to the default ad unit configured for the specified `tenantId`.