added brave bidder docs (#3181)

* added brave bidder docs

* added quotes around the string parameter

Co-authored-by: bretg <bgorsline@gmail.com>

dev-docs/bidders/brave.md

@@ -0,0 +1,26 @@
+---
+layout: bidder
+title: Brave
+description: Prebid Brave Bidder Adapter
+biddercode: brave
+gdpr_supported: true
+usp_supported: true
+coppa_supported: true
+schain_supported: true
+media_types: banner, video, native
+safeframes_ok: true
+bidder_supports_deals: true
+pbjs: true
+pbs: false
+---
+
+### Note:
+
+The Brave Header Bidding adapter requires setup and approval from the Brave team. Please reach out to your account manager or support@thebrave.io for more information
+
+### Bid Params
+
+{: .table .table-bordered .table-striped }
+| Name          | Scope    | Description                   | Example                             | Type      |
+|---------------|----------|-------------------------------|-------------------------------------|-----------|
+| `placementId` | required | Brave's platform placement id | `'to0QI2aPgkbBZq6vgf0oHitouZduz0qw'`  | `string`  |