Add Pubnative bidder documentation (prebid#1340)

docs/bidders/pubnative.md

@@ -0,0 +1,62 @@
+# Pubnative Bidder
+
+## Prerequisite
+Before adding PubNative as a new bidder, there are 3 prerequisites:
+- As a Publisher, you need to have Prebid Mobile SDK integrated.
+- You need a configured Prebid Server (either self-hosted or hosted by 3rd party).
+- You need to be integrated with Ad Server SDK (e.g. Mopub) or internal product which communicates with Prebid Mobile SDK.
+
+Please see [documentation](https://developers.pubnative.net/docs/prebid-adding-pubnative-as-a-bidder) for more info.
+
+## Configuration 
+
+- bidder should be always set to "pubnative" (`imp.ext.pubnative`)
+- zone_id (int) should be always set to 1, unless special use case agreed with our account manager. (`imp.ext.pubnative.zone_id`)
+- app_auth_token (string) is unique per publisher app. Please contact our account manager to obtain yours. (`imp.ext.pubnative.app_auth_token`)
+
+An example is illustrated in a section below.
+
+## Testing
+
+Please consult with our Account Manager for testing. 
+We need to confirm that your ad request is correctly received by our system.
+
+The following test parameters can be used to verify that Prebid Server is working properly with the 
+Pubnative adapter.
+
+The following json can be used to do a request to prebid server for verifying its integration with Pubnative adapter.
+
+```json
+{
+    "id": "some-impression-id",
+    "site": {
+      "page": "https://good.site/url"
+    },
+    "imp": [
+      {
+        "id": "test-imp-id",
+        "banner": {
+          "format": [
+            {
+              "w": 300,
+              "h": 250
+            }
+          ]
+        },
+        "ext": {
+          "pubnative": {
+            "zone_id": 1,
+            "app_auth_token": "b620e282f3c74787beedda34336a4821"
+          }
+        }
+      }
+    ],
+    "device": {
+      "os": "android",
+      "h": 700,
+      "w": 375
+    },
+    "tmax": 500,
+    "test": 1
+}
+```