Upgrade kf_config.json to v2 (nested config + dtype)

kf_config.json

@@ -1,23 +1,29 @@
 {
   "library_name": "kerasformers",
-  "kerasformers_version": "1.1.3",
+  "kerasformers_version": "1.2.1",
   "model_module": "kerasformers.models.clip",
   "model_class": "CLIPZeroShotClassify",
   "variant": "clip_vit_base_32",
   "weights": "model.weights.h5",
+  "schema_version": 2,
+  "dtype": "float32",
   "model_type": "clip",
+  "text_config": {
+    "hidden_dim": 512,
+    "num_heads": 8,
+    "num_layers": 12,
+    "mlp_ratio": 4.0,
+    "vocab_size": 49408,
+    "max_seq_len": 77
+  },
+  "vision_config": {
+    "num_layers": 12,
+    "hidden_dim": 768,
+    "patch_size": 32,
+    "mlp_ratio": 4.0,
+    "image_size": 224
+  },
   "embed_dim": 512,
-  "image_size": 224,
-  "vision_num_layers": 12,
-  "vision_hidden_dim": 768,
-  "vision_patch_size": 32,
-  "max_seq_len": 77,
-  "vocab_size": 49408,
-  "text_hidden_dim": 512,
-  "text_num_heads": 8,
-  "text_num_layers": 12,
-  "vision_mlp_ratio": 4.0,
-  "text_mlp_ratio": 4.0,
   "hidden_act": "quick_gelu",
   "layer_norm_eps": 1e-05
 }