Add Impactify bidder documentation

dev-docs/bidders/impactify.md

@@ -0,0 +1,59 @@
+---
+layout: bidder
+title: Impactify
+description: Prebid Impactify Bidder Adapter
+pbjs: true
+pbs: false
+biddercode: impactify
+gdpr_supported: true
+tcf2_supported: true
+usp_supported: true
+schain_supported: true
+coppa_supported: true
+media_types: video
+gvl_id: 606
+---
+
+### Note:
+
+The Impactify adaptator requires setup and validation from the Impactify team. Simply email us your contact details at support@impactify.io and we'll make sure we'll connect you within 48h.
+
+### Bid Params
+
+{: .table .table-bordered .table-striped }
+| Name          | Scope    | Description                                        | Example        | Type      |
+|---------------|----------|----------------------------------------------------|----------------|-----------|
+| `appId`       | required | Impactify publisher id  (Contact us)               | `'example.com'`  | `string`  |
+| `format`      | required | Impactify ad format (screen or display)            | `'screen'`       | `string`  |
+| `style`       | required | Impactify ad style (inline, impact or static)      | `'impact'`       | `string`  |
+
+### Configuration
+
+Impactify recommends the UserSync configuration below. Without it, the Impactify adapter will not be able to perform user syncs, which lowers match rate and reduces monetization.
+
+For Prebid.js v1.15.0 and later:
+
+```javascript
+pbjs.setConfig({
+  userSync: {
+    filterSettings: {
+      iframe: {
+        bidders: '*',      // '*' represents all bidders
+        filter: 'include'
+      }
+    }
+  }
+});
+```
+
+For Prebid.js v1.14.0 and before:
+
+```javascript
+pbjs.setConfig({
+   userSync: {
+    iframeEnabled: true,
+    enabledBidders: ['impactify']
+ }});
+```
+
+Note: Combine the above configuration with any other UserSync configuration. Multiple setConfig() calls overwrite each other and only the last call for a given attribute will take effect.