no-mistakes(document): Point duplicate key-loading docs to README owner

Author: Bre77

docs/bluetooth_vehicles.md

@@ -39,11 +39,9 @@ async def main():
 asyncio.run(main())
 ```
 
-`get_private_key(path)` loads an existing EC private key or creates a new
-unencrypted PEM key file. Newly created key files are created owner-readable
-and owner-writable only (`0600`) from the start, with no write-then-chmod
-window, and concurrent creators fall back to reading the file that won the
-create race.
+See the [README](../README.md#bluetooth-for-vehicles) for
+`get_private_key(path)`'s create/load semantics and the `PrivateKeyError`
+raised for an unusable existing key file.
 
 ## Keeping the Connection Alive (`keepalive_interval`)
 

docs/fleet_api_energy_sites.md

@@ -397,10 +397,9 @@ an empty or `null` response even when it is not useful for proving local key
 readiness.
 
 `get_rsa_private_key(path)` loads an existing RSA private key for gateway
-client registration or creates a new unencrypted PEM key file. Newly created
-key files are created owner-readable and owner-writable only (`0600`) from the
-start, with no write-then-chmod window, and concurrent creators fall back to
-reading the file that won the create race.
+client registration or creates a new unencrypted PEM key file; see the
+[README](../README.md#bluetooth-for-vehicles) for its create/load semantics
+and the `PrivateKeyError` raised for an unusable existing key file.
 
 ### Available Commands