add torchscript model and config json

Adds a torchscript version of the prostate adenocarcinoma model.

```python
import torch
import wsinfer

w = wsinfer.get_model_weights('resnet34', 'TCGA-PRAD-v1')
model = w.load_model()
c = torch.jit.script(model, example_inputs=[(torch.ones(1, 3, w.transform.resize_size, w.transform.resize_size),)])
torch.jit.save(c, root / w.url_file_name)
```

config.json

@@ -0,0 +1,23 @@
+{
+    "num_classes": 3,
+    "transform": {
+        "resize_size": 224,
+        "mean": [
+            0.6462,
+            0.507,
+            0.8055
+        ],
+        "std": [
+            0.1381,
+            0.1674,
+            0.1358
+        ]
+    },
+    "patch_size_pixels": 175,
+    "spacing_um_px": 0.5,
+    "class_names": [
+        "grade3",
+        "grade4+5",
+        "benign"
+    ]
+}

torchscript_model.pt

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ea5475460f06461b8d0059d1a848f4e975d0fa25b2b7dd64c514d05365451e35
+size 85345884