Add missing directories in data organization documentation

Author: WCJ-BERT

docs/data_organization.md

@@ -123,6 +123,8 @@ Data for closed-loop simulation.
 data/sim_engine/
 ├── assets/                        # Scene assets for simulation
 │   ├── navtest
+│   │   ├── assets
+│   │   └── configs
 │   ├── navtrain
 │   └── navtest_failures
 │
@@ -188,4 +190,4 @@ Apply changes:
 source ~/.bashrc  # or source ~/.zshrc
 ```
 
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+---