Add new adapter - Brainx (#5689)

* add brainx md

* edit mediaTye

* Change the email address to BrainX official email address and change the endpint to optional

* delete brainx.md aliasCode

* Update brainx.md

* added missing quotes

* update endpoint url

---------

Co-authored-by: hugh.qu <[email protected]>
Co-authored-by: bretg <[email protected]>

dev-docs/bidders/brainx.md

@@ -0,0 +1,37 @@
+---
+layout: bidder
+title: brainx
+description: Prebid brainx Bidder Adapter
+biddercode: brainx
+tcfeu_supported: false
+dsa_supported: false
+gvl_id: none
+usp_supported: false
+coppa_supported: false
+gpp_sids: none
+schain_supported: true
+dchain_supported: false
+media_types: banner
+safeframes_ok: false
+deals_supported: true
+floors_supported: true
+fpd_supported: false
+pbjs: true
+pbs: false
+prebid_member: false
+multiformat_supported: will-bid-on-any
+ortb_blocking_supported: true
+sidebarType: 1
+---
+
+### Registration
+
+If you have any questions regarding set up, please reach out to your account manager or <[email protected]>.
+
+### Bid Parameters
+
+{: .table .table-bordered .table-striped }
+| Name       | Scope        | Description                          | Example                                | Type     |
+| ---------- | ------------ | ------------------------------------ | -------------------------------------- | -------- |
+| `pubId`    | required     | Placement Id                         | `F7B53DBC-85C1-4685-9A06-9CF4B6261FA3` | `string` |
+| `endpoint` | Not required | The endpoint provided by Brainx Url. | `https://dsp.brainx.tech/bid`          | `string` |