Documentation for Kobler bidder adapter (#2806)

* Documentation for Kobler bidder adapter.

* Added information on how to generate a sample bid.

* Removed reading currency from currency.adServerCurrency.

dev-docs/bidders/kobler.md

@@ -0,0 +1,72 @@
+---
+layout: bidder
+title: Kobler
+description: Kobler Bidder Adapter
+biddercode: kobler
+pbjs: true
+media_types: banner
+getFloor: true
+bidder_supports_deals: true
+---
+
+### Note:
+
+The Kobler Bidder Adapter requires setup and approval from Kobler AS.
+Please reach out to <bidding-support@kobler.no> for more information.
+
+### Bid Params
+
+{: .table .table-bordered .table-striped }
+| Name          | Scope    | Description                                                                                                                                                                                                                                    | Example                      | Type               |
+|---------------|----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------|--------------------|
+| `placementId` | required | The identifier of the placement, it has to be issued by Kobler.                                                                                                                                                                                | `'xjer0ch8'`                 | `string`           |
+| `zip`         | optional | Zip code of the user or the medium. When multiple ad units are submitted together, it is enough to set this parameter on the first one.                                                                                                        | `'102 22'`                   | `string`           |
+| `test`        | optional | Whether the request is for testing only. When multiple ad units are submitted together, it is enough to set this parameter on the first one. Defaults to false.                                                                                | `true`                       | `boolean`          |
+| `floorPrice`  | optional | Floor price in CPM and in USD. Can be used as an alternative to the [Floors module](https://docs.prebid.org/dev-docs/modules/floors.html), which is also supported by this adapter. Defaults to 0. | `5.0`                        | `float`            |
+| `position`    | optional | The position of the ad unit. Can be used to differentiate between ad units if the same placement ID is used across multiple ad units. Defaults to 0.                                                                                           | `1`                          | `string`           |
+| `dealIds`     | optional | Array of deal IDs.                                                                                                                                                                                                                             | `['abc328745', 'mxw243253']` | `array of strings` |
+
+### Example
+```javascript
+  const adUnits = [{
+    code: 'div-gpt-ad-1460505748561-1',
+    mediaTypes: {
+        banner: {
+            sizes: [[320, 250], [300, 250]],
+        }
+    },
+    bids: [{
+      bidder: 'kobler',
+      params: {
+        placementId: 'k5H7et3R0'
+      }
+    }]
+  }];
+```
+
+In order to see a sample bid from Kobler (without a proper setup), you have to also do the following:
+- Change the [`refererInfo` function](https://github.com/prebid/Prebid.js/blob/master/src/refererDetection.js) to return `'https://www.tv2.no/a/11734615'` as a [`referer`](https://github.com/prebid/Prebid.js/blob/caead3ccccc448e4cd09d074fd9f8833f56fe9b3/src/refererDetection.js#L169). This is necessary because Kobler only bids on recognized articles. 
+- Change the adapter's [`BIDDER_ENDPOINT`](https://github.com/prebid/Prebid.js/blob/master/modules/koblerBidAdapter.js#L8) to `'https://bid-service.dev.essrtb.com/bid/prebid_rtb_call'`. This endpoint belongs to the development server that is set up to always return a bid for the correct `placementId` and page URL combination. 
+
+### Example With Optional Parameters
+```javascript
+  const adUnits = [{
+    code: 'div-gpt-ad-1460505748561-1',
+    mediaTypes: {
+        banner: {
+            sizes: [[320, 250], [300, 250]],
+        }
+    },
+    bids: [{
+      bidder: 'kobler',
+      params: {
+        placementId: 'k5H7et3R0',
+        zip: '102 22',
+        test: true,
+        floorPrice: 5.0,
+        position: 1,
+        dealIds: ['abc328745', 'mxw243253']
+      }
+    }]
+  }];
+```