Add FreePass IdSystem Docs

dev-docs/modules/userId.md

@@ -212,6 +212,7 @@ Bidders that want to support the User ID module in Prebid.js need to update thei
 | SharedID (PBJS 4.x)| Prebid | sharedid | sharedid.org | {"id":"01EAJWWN...", "third":"01EAJ..."} |
 | Unified ID | Trade Desk | tdid | adserver.org | "1111" |
 | ConnectID | Yahoo | connectId | yahoo.com | {"connectId": "72d04af6..."} |
+| FreePass ID | FreePass | freepassId | | "1111" |
 
 For example, the adapter code might do something like:
 

dev-docs/modules/userid-submodules/freepass.md

@@ -0,0 +1,47 @@
+---
+layout: userid
+title: FreePass ID
+description: FreePass User ID sub-module
+useridmodule: freepassIdSystem
+---
+
+[FreePass](https://freepass-login.com/introduction.html) is a common authentication service operated by Freebit Co., Ltd. Users with a FreePass account do not need to create a new account to use partner services.
+
+Please contact FreePass before using this ID at [[email protected]](mailto:[email protected])
+
+## FreePass ID Configuration
+
+Please make sure to add the FreePass user ID sub-module to your Prebid.js package with:
+
+```shell
+gulp build --modules=freepassIdSystem,userId
+```
+
+The following configuration parameters are available:
+
+{: .table .table-bordered .table-striped }
+| Param under userSync.userIds[] | Scope    | Type   | Description                                          | Example        |
+|--------------------------------|----------|--------|------------------------------------------------------|----------------|
+| name                           | Required | String | The name of this module                              | `"freepassId"` |
+| freepassData                   | Optional | Object | FreePass data                                        | `{}`           |
+| freepassData.commonId          | Optional | String | Common ID obtained from FreePass                     | `"abcd1234"`   |
+| freepassData.userIp            | Optional | String | User IP obtained in cooperation with partner service | `"127.0.0.1"`  |
+
+Usage example:
+
+```javascript
+pbjs.setConfig({
+    userSync: {
+        userIds: [{
+            name: 'freepassId',
+            storage: { name: '_freepassId', type: 'cookie', expires: 30 },
+            params: {
+                freepassData: {
+                    commonId: 'fpcommonid123',
+                    userIp: '127.0.0.1'
+                }
+            }
+        }]
+    }
+});
+```