Add SmolLM3 (#349)

* feat: Add SmolLM3
* Update swift-transformers to 0.1.22

Author: johnmai-dev

ACKNOWLEDGMENTS.md

@@ -6,7 +6,7 @@
 
 MLX Swift was developed with contributions from the following individuals:
 
-- [John Mai](https://github.com/johnmai-dev): Added support for multiple models (Qwen2, Starcoder2, InternLM2, Qwen3, Qwen3 MoE, GLM-4, MiMo, BitNet).
+- [John Mai](https://github.com/johnmai-dev): Added support for multiple models (Qwen2, Starcoder2, InternLM2, Qwen3, Qwen3 MoE, GLM-4, MiMo, BitNet, SmolLM3).
 
 
 <a href="https://github.com/ml-explore/mlx-swift-examples/graphs/contributors">

Libraries/MLXLLM/LLMModelFactory.swift

@@ -49,6 +49,7 @@ public class LLMTypeRegistry: ModelTypeRegistry, @unchecked Sendable {
             "glm4": create(GLM4Configuration.self, GLM4Model.init),
             "acereason": create(Qwen2Configuration.self, Qwen2Model.init),
             "bitnet": create(BitnetConfiguration.self, BitnetModel.init),
+            "smollm3": create(SmolLM3Configuration.self, SmolLM3Model.init),
             "ernie4_5": create(Ernie45Configuration.self, Ernie45Model.init),
         ]
     }
@@ -232,6 +233,11 @@ public class LLMRegistry: AbstractModelRegistry, @unchecked Sendable {
         defaultPrompt: "Why is the sky blue?"
     )
 
+    static public let smollm3_3b_4bit = ModelConfiguration(
+        id: "mlx-community/SmolLM3-3B-4bit",
+        defaultPrompt: "Why is the sky blue?"
+    )
+
     static public let ernie_45_0_3BPT_bf16_ft = ModelConfiguration(
         id: "mlx-community/ERNIE-4.5-0.3B-PT-bf16-ft",
         defaultPrompt: "Why is the sky blue?"
@@ -269,6 +275,7 @@ public class LLMRegistry: AbstractModelRegistry, @unchecked Sendable {
             glm4_9b_4bit,
             acereason_7b_4bit,
             bitnet_b1_58_2b_4t_4bit,
+            smollm3_3b_4bit,
             ernie_45_0_3BPT_bf16_ft,
         ]
     }