smartx Bid Adapter: refactor descriptions and adding "visibilityThreshold"

dev-docs/bidders/smartx.md

@@ -43,10 +43,11 @@ Please reach out to your smartclip business contact for any questions and assist
 | Name            | Scope    | Description                                                                                  | Example          | Type        |
 | --------------- | -------- | -------------------------------------------------------------------------------------------- | ---------------- | ----------- |
 | `slot`          | required | ID of element that video ad should be rendered into.                                         | `'adSlot1'`      | `string`    |
-| `minAdWidth`    | optional | Minimum amount of space the player needs to expand.                                          | `290`            | `integer`   |
-| `maxAdWidth`    | optional | Maximum size of the player.                                                                  | `900`            | `integer`   |
-| `title`         | optional | Makes a defined advertising text appear in the below right corner. `[remainingTime]` can be used to display the remaining time of the advertisement. | `'Advertisement [remainingTime]s'` | `string`    |
-| `skipOffset`    | optional | Define whenever the advertisement can be skipped. 0 = never                                  | `0`              | `integer`   |
-| `startOpen`     | optional | Define whether the player should be initialized open or open when it is within view.         | `'false'`        | `string`    |
-| `endingScreen`  | optional | Define whether the player should stay open after advertising or not.                         | `'true'`         | `string`    |
-| `desiredBitrate`| optional | Define the desired bitrate of the mediafile.                                                 | `800`            | `integer`   |
+| `minAdWidth`    | optional | If the visible area is narrower than this size, no ad will be requested. The value is given in pixels. Default is `280`.       | `290`            | `integer`   |
+| `maxAdWidth`    | optional | The player will fill the whole width of the element it gets, to have it narrower a different maximum width can be defined in pixels. Default is `800`.                                | `900`            | `integer`   |
+| `title`         | optional | The player can show a freely definable text, a macro `[remainingTime]` in this string will be replaced with the remaining play time of the ad in seconds. | `'Advertisement [remainingTime]s'` | `string`    |
+| `skipOffset`    | optional | In order to enable skipping from the start set the delay to `0`, to show the skip button after 5 seconds set it to `5`. Setting a general skipOffset is discouraged. Note that linear creatives carrying a skipsoffet attribute will override the general player setting. By default the player does not set a general skipoffset, so a skip button will only be shown, if an ad has a specific skipoffset attached. |  `0`  | `integer`   |
+| `startOpen`     | optional | Per default the player will start fully expanded, if a valid ad can be played. Setting this option to `false` will trigger an expand animation instead once the player comes into view. Default is `true`.              | `'false'`        | `string`    |
+| `endingScreen`  | optional | By default the player will not close, but show the ending screen when an advertisement is complete (last frame of the ad and a replay button, if an advertisment comes with an endcard that will be shown). If set to `false` the player will collapse. Some VPAID creatives can cause issues with ending screen or replay behaviour. Default is `true`.              | `'true'`         | `string`    |
+| `desiredBitrate`| optional | You can specify a target bitrate for the creative, higher values will increase video quality but will cost bandwidth. Value is given in kpbs. Default is `700`.                       | `800`            | `integer`   |
+| `visibilityThreshold`| optional | Defines the percentage of the player which has to be in the visible area to play and pause the advertisment. The default is `50`.                           | `50`             | `integer`   |