Add doc for role bindings

Signed-off-by: Shawn Wang <[email protected]>

website/docs/r/policy_user_management_role_binding.html.markdown

@@ -0,0 +1,77 @@
+---
+subcategory: "Beta"
+layout: "nsxt"
+page_title: "NSXT: nsxt_policy_user_management_role_binding"
+description: A resource to configure user management Role Bindings.
+---
+
+# nsxt_policy_user_management_role_binding
+
+This resource provides a method for the management of Role Bindings of users.
+
+## Example Usage
+
+```hcl
+resource "nsxt_policy_user_management_role_binding" "test" {
+    display_name = "[email protected]"
+    name = "[email protected]"
+    type = "remote_user"
+    identity_source_type = "LDAP"
+    
+    roles_for_path {
+        path = "/"
+        role {
+            role = "auditor"
+        }
+    }
+    
+    roles_for_path {
+        path = "/orgs/default"
+        role {
+            role = "org_admin"
+        }
+        role {
+            role = "vpc_admin"
+        }
+    }
+}
+```
+
+## Argument Reference
+
+The following arguments are supported:
+
+* `display_name` - (Optional) Display name of the resource.
+* `description` - (Optional) Description of the resource.
+* `tag` - (Optional) A list of scope + tag pairs to associate with this resource.
+* `name` - (Required) User/Group's name.
+* `type` - (Required) Indicates the type of the user. Valid options:
+    * `remote_user` - This is a user which is external to NSX. 
+    * `remote_group` - This is a group of users which is external to NSX.
+    * `local_user` - This is a user local to NSX. These are linux users. Note: Role bindings for local users are owned by NSX. Creation and deletion is not allowed for local users' binding. For updates, import existing bindings first.
+    * `principal_identity` - This is a principal identity user.
+* `identity_source_type` - (Optional) Identity source type. Applicable only to `remote_user` and `remote_group` user types. Valid options are: `VIDM`, `LDAP`, `OIDC`, `CSP`. Defaults to `VIDM` when applicable.
+* `identity_source_id` - (Optional) The ID of the external identity source that holds the referenced external entity. Currently, only external `LDAP` and `OIDC` servers are allowed.
+* `roles_for_path` - (Required) A list of The roles that are associated with the user, limiting them to a path. In case the path is '/', the roles apply everywhere.
+    * `path` - (Required) Path of the entity in parent hierarchy.
+    * `role` - (Required) A list of identifiers for the roles to associate with the given user limited to a path.
+
+## Attributes Reference
+
+In addition to arguments listed above, the following attributes are exported:
+
+* `id` - ID of the resource.
+* `revision` - Indicates current revision number of the object as seen by NSX-T API server. This attribute can be useful for debugging.
+* `user_id` - Local user's numeric id. Only applicable to `local_user`.
+
+
+## Importing
+
+An existing object can be [imported][docs-import] into this resource, via the following command:
+
+[docs-import]: https://www.terraform.io/cli/import
+
+```
+terraform import nsxt_policy_user_management_role_binding.test ROLE_BINDING_ID
+```
+The above command imports Role named `test` with the role binding identifier `ROLE_BINDING_ID`.