Add support for Puffin-Phi-v2. (#1110)

* Add support for Puffin-Phi-v2.

* Tweak the file name.

* Support the config for puffin-phi-v2.

* Update the readme.

candle-transformers/src/models/mixformer.rs

@@ -55,6 +55,23 @@ impl Config {
             pad_vocab_size_multiple: 64,
         }
     }
+
+    // https://huggingface.co/teknium/Puffin-Phi-v2/blob/main/config.json
+    pub fn puffin_phi_v2() -> Self {
+        Self {
+            vocab_size: 50304,
+            n_positions: 2048,
+            n_embd: 2048,
+            n_layer: 24,
+            n_inner: None,
+            n_head: 32,
+            rotary_dim: usize::min(32, 2048 / 32),
+            activation_function: Activation::Gelu,
+            layer_norm_epsilon: 1e-5,
+            tie_word_embeddings: false,
+            pad_vocab_size_multiple: 64,
+        }
+    }
 }
 
 #[derive(Debug)]