Add config.json (model hyperparameters; enables download tracking)

config.json

@@ -0,0 +1,23 @@
+{
+  "architecture": "JiT_T2I",
+  "checkpoint": "PixelDense_XXL_T2I.ckpt",
+  "checkpoint_key_prefix": "ema_denoiser.",
+  "patch_size": 16,
+  "input_size": 512,
+  "in_channels": 3,
+  "hidden_size": 1536,
+  "num_blocks": 16,
+  "num_groups": 24,
+  "txt_embed_dim": 2048,
+  "txt_max_length": 128,
+  "bottleneck_dim": 256,
+  "num_text_blocks": 4,
+  "text_encoder": "Qwen/Qwen3-1.7B",
+  "sampler": {
+    "name": "AdamLMSamplerJiT",
+    "num_steps": 25,
+    "guidance": 4.0,
+    "timeshift": 3.0,
+    "order": 2
+  }
+}