Update Dart SDK status to Supported

Author: NathanTarbert

docs/introduction.mdx

@@ -280,11 +280,11 @@ AG-UI was born from CopilotKit's initial partnership with LangGraph and CrewAI -
 | :-- | ------- | ---------------- | ------------- |
 | [Kotlin]() | Supported | [Getting Started](https://github.com/ag-ui-protocol/ag-ui/blob/main/docs/sdk/kotlin/overview.mdx) | Community |
 | [Golang]() | Supported | [Getting Started](https://github.com/ag-ui-protocol/ag-ui/blob/main/docs/sdk/go/overview.mdx) | Community |
+| [Dart]() | Supported | [Getting Started](https://github.com/ag-ui-protocol/ag-ui/tree/main/sdks/community/dart) | Community |
 | [Java]() | Supported | [Getting Started](https://github.com/ag-ui-protocol/ag-ui/blob/main/docs/sdk/java/overview.mdx) | Community |
 | [Rust]() | Supported | [Getting Started](https://github.com/ag-ui-protocol/ag-ui/tree/main/sdks/community/rust/crates/ag-ui-client) | Community |
 | [.NET]() | In Progress | [PR](https://github.com/ag-ui-protocol/ag-ui/pull/38) | Community |
 | [Nim]() | In Progress | [PR](https://github.com/ag-ui-protocol/ag-ui/pull/29) | Community |
-| [Dart]() | In Progress | [PR](https://github.com/ag-ui-protocol/ag-ui/pull/432) | Community |
 | [Flowise]() | In Progress | [GitHub Source](https://github.com/ag-ui-protocol/ag-ui/issues/367) | Community |
 | [Langflow]() | In Progress | [GitHub Source](https://github.com/ag-ui-protocol/ag-ui/issues/366) | Community |