Add Qwen3 MoE (#2934)

* qwen-moe rebase

* lint

* fixed rebase error

* swapped normal MoE model with CausalMoE Model in example, and swapped the tie word embeddings if statement

* updated readme

candle-transformers/src/models/mod.rs

@@ -100,6 +100,7 @@ pub mod quantized_t5;
 pub mod qwen2;
 pub mod qwen2_moe;
 pub mod qwen3;
+pub mod qwen3_moe;
 pub mod recurrent_gemma;
 pub mod repvgg;
 pub mod resnet;