Match Moondream's latest release (#1997)

* moondream implementation

* add moondream example

* change config default activation

* Add assets and integrate phi mixformer with example

* Make use of kv cache and fix seq_len bug; Clean up example code

* Add README link to example

* Remove pos_embed scaling; Remove assets; Add to README; Expand VisionConfig

* Delete image

* Use apply instead of forward

* Use latest release special token; Fix token/s accuracy; Use GeluPytorchTanh in VisionConfig v2

candle-transformers/src/models/moondream.rs

@@ -47,7 +47,7 @@ impl VisionConfig {
             embed_dim: 1152,
             num_blocks: 27,
             num_heads: 16,
-            act: candle_nn::Activation::Gelu,
+            act: candle_nn::Activation::GeluPytorchTanh,
         }
     }
 }