Add doc for data keycloak_authentication_flow

docs/data-sources/authentication_flow.md

@@ -0,0 +1,32 @@
+---
+page_title: "keycloak_authentication_flow Data Source"
+---
+
+# keycloak\_authentication\_flow Data Source
+
+This data source can be used to fetch the ID of an authentication flow within Keycloak.
+
+## Example Usage
+
+```hcl
+resource "keycloak_realm" "realm" {
+    realm   = "my-realm"
+    enabled = true
+}
+
+data "keycloak_authentication_flow" "browser_auth_cookie" {
+  realm_id          = keycloak_realm.realm.id
+  parent_flow_alias = "browser"
+  provider_id       = "auth-cookie"
+}
+```
+
+## Argument Reference
+
+- `realm_id` - (Required) The realm the authentication flow exists in.
+- `parent_flow_alias` - (Required) The alias of the flow this flow is attached to.
+- `provider_id` - (Required) The name of the provider. This can be found by experimenting with the GUI and looking at HTTP requests within the network tab of your browser's development tools. This was previously known as the "authenticator".
+
+## Attributes Reference
+
+- `id` - (Computed) The unique ID of the authentication flow, which can be used as an argument to other resources supported by this provider.