add mistral to OpenNMT-py converter (#1541)

python/ctranslate2/converters/opennmt_py.py

@@ -103,8 +103,12 @@ def _get_model_spec_lm(opt, variables, src_vocabs, tgt_vocabs, num_source_embedd
     with_alibi = getattr(opt, "max_relative_positions", 0) == -2
     activation_fn = getattr(opt, "pos_ffn_activation_fn", "relu")
     num_heads = getattr(opt, "heads", 8)
+    num_kv = getattr(opt, "num_kv", 0)
+    if num_kv == num_heads:
+        num_kv = None
     rotary_dim = 0 if with_rotary else None
     ffn_glu = activation_fn == "silu"
+    sliding_window = getattr(opt, "sliding_window", 0)
 
     model_spec = transformer_spec.TransformerDecoderModelSpec.from_config(
         opt.dec_layers,
@@ -117,8 +121,12 @@ def _get_model_spec_lm(opt, variables, src_vocabs, tgt_vocabs, num_source_embedd
         rotary_dim=rotary_dim,
         rotary_interleave=True,
         multi_query_attention=getattr(opt, "multiquery", False),
+        num_heads_kv=num_kv,
+        sliding_window=sliding_window,
     )
 
+    model_spec.config.layer_norm_epsilon = getattr(opt, "norm_eps", 1e-6)
+
     set_transformer_decoder(
         model_spec.decoder,
         variables,