Enable Hugging Face download counting

README.md

@@ -36,11 +36,12 @@ a visible-device subset compatible with its walker batch.
 ## Foundation checkpoint
 
 This Hugging Face repository stores the directly loadable HamiltonZero v1
-foundation checkpoint at `weights/hamiltonzero_v1.eqx`. To download the
-checkpoint without cloning the repository:
+foundation checkpoint at `weights/hamiltonzero_v1.eqx`, with its manifest in
+`config.json`. To download both files without cloning the repository:
 
 ```bash
 hf download simulacra-research/HamiltonZero \
+  config.json \
   weights/hamiltonzero_v1.eqx \
   --local-dir .
 ```

config.json

@@ -0,0 +1,7 @@
+{
+  "checkpoint": "weights/hamiltonzero_v1.eqx",
+  "checkpoint_kind": "router",
+  "format": "equinox.tree_serialise_leaves",
+  "package": "hamiltonzero",
+  "package_version": "0.1.0"
+}