Add rumble bidder docs (prebid#6139)

* Add rumble bidder docs

* Remove multi-line break

* Add additional metadata flags

Author: EwalksRumble

dev-docs/bidders/rumble.md

@@ -0,0 +1,41 @@
+---
+layout: bidder
+title: Rumble Advertising Center
+description: Prebid Rumble Bidder Adapter
+biddercode: rumble
+tcfeu_supported: false
+dsa_supported: false
+gvl_id: none
+usp_supported: true
+coppa_supported: false
+gpp_sids: none
+schain_supported: false
+dchain_supported: false
+media_types: video
+safeframes_ok: true
+floors_supported: true
+fpd_supported: false
+pbjs: true
+pbs: false
+prebid_member: false
+multiformat_supported: will-bid-on-one
+ortb_blocking_supported: false
+privacy_sandbox: no
+sidebarType: 1
+---
+
+### Note
+
+To use the Rumble Advertising Center bidder, you need to have an existing Rumble Advertising Center account. To create a 
+new account, see <https://ads.rumble.com>. For additional help, contact support or your account representative.
+
+### Bid Params
+
+{: .table .table-bordered .table-striped }
+
+| Name        | Scope    | Description                                             | Example  | Type       |
+|-------------|----------|---------------------------------------------------------|----------|------------|
+| publisherId | required | Account publishing ID                                   | `1234`   | `number`   |  
+| siteId      | required | The site ID you want to send requests                   | `123`    | `number`   |
+| zoneId      | optional | An optional zone ID that you want to force requests to  | `12`     | `number`   |      
+| test        | optional | An optional boolean flag for sending test requests      | `true`   | `boolean`  |