Sharethrough: Schain bidfloor adapter docs update (#1533)

* Support the schain module

* List Sharethrough adapter support for schain module + bidfloor param

* Update documentation to specify that bidfloor should only be a float

Author: madma

dev-docs/bidders/sharethrough.md

@@ -7,6 +7,7 @@ biddercode: sharethrough
 media_types: native
 gdpr_supported: true
 userIds: unifiedId/tradedesk
+schain_supported: true
 ---
 
 ### Note:
@@ -15,8 +16,9 @@ The Sharethrough bidder adapter requires additional setup and approval from the
 ### Bid Params
 
 {: .table .table-bordered .table-striped }
-| Name         | Scope    | Description                                                                                                                                                                                                                                                           | Example                      | Type             |
-|--------------|----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------|------------------|
-| `pkey`       | required | The placement key                                                                                                                                                                                                                                                     | `'DfFKxpkRGPMS7A9f71CquBgZ'` | `string`         |
-| `iframe`     | optional | If `true`, the ad will render in an iframe. Defaults to `false`.                                                                                                                                                                                                      | `true`                       | `boolean`        |
-| `iframeSize` | optional | `[width, height]` If provided, use this size for the iframe size. Only applicable if `iframe` is `true`. If omitted, the largest size from the ad unit sizes array will be used.                                                                                      | `[300, 250]`                 | `Array<integer>` |
+| Name | Scope | Description | Example | Type
+| ---- | ----- | ----------- | ------- | ----
+| `pkey` | required | The placement key | `'DfFKxpkRGPMS7A9f71CquBgZ'` | `string`
+| `iframe` | optional | If `true`, the ad will render in an iframe. Defaults to `false`. | `true` | `boolean`
+| `iframeSize` | optional | `[width, height]` If provided, use this size for the iframe size. Only applicable if `iframe` is `true`. If omitted, the largest size from the ad unit sizes array will be used. | `[300, 250]` | `[integer]`
+| `bidfloor` | optional | The floor price, or minimum amount, a publisher will accept for an impression, given in CPM in USD. | `1.00` | `float`