docs: add concrete repo tree to README

README.md

@@ -39,6 +39,42 @@ Each directory contains `<name>.safetensors` (weights),
 `<name>.config.json` (training hparams + quality metrics), and `<name>.md`
 (one-page model card). The metadata format is unified across all artifacts.
 
+## Repository tree
+
+```
+.
+├── README.md
+│
+├── attribution/pythia-160m/
+│   ├── induction-{results.pt, verdict.json}
+│   ├── ioi-{results.pt, verdict.json}
+│   └── sva-{results.pt, verdict.json}
+│
+├── pythia-160m/
+│   ├── W_E/cross-snapshot-32/
+│   │   ├── d8192/seed{0..4}.{safetensors, config.json, md}
+│   │   └── d24576/seed0.{safetensors, config.json, md}
+│   │
+│   └── W_U/
+│       ├── cross-snapshot-32/
+│       │   ├── d8192/seed{0..4}.{safetensors, config.json, md}
+│       │   ├── d16384/seed0.{safetensors, config.json, md}
+│       │   └── d24576/seed{0..2}.{safetensors, config.json, md}
+│       │
+│       ├── cross-snapshot-16/d8192/seed0.{...}
+│       │
+│       ├── per-snapshot-saes/d8192/step{0..143000}.{safetensors, config.json, md}   # 32 snapshots
+│       │
+│       ├── architecture-comparison/d8192/
+│       │   ├── batchtopk/seed0.{...}
+│       │   ├── gated/seed0.{...}
+│       │   └── gated-retuned/seed0.{...}
+│       │
+│       └── final-snapshot-saes/d{6144, 8192, 16384, 32768, 65536}.{safetensors, config.json, md}
+│
+└── pythia-1b/W_U/cross-snapshot-32/d{8192, 16384, 24576}/seed0.{safetensors, config.json, md}
+```
+
 ## Quick start
 
 ```python