chore: update .env.example with torch setting

Author: atrifat

.env.example

@@ -10,4 +10,7 @@ DETOXIFY_MODEL=unbiased-small
 ENABLE_CACHE=false
 
 # (Optional. Default: 60. Options: integer value) Duration of cache in seconds. Parameter will be used when the cache is enabled
-CACHE_DURATION_SECONDS=60
+CACHE_DURATION_SECONDS=60
+
+# (Optional. Default: auto. Options: auto,cpu,cuda) Set torch default device for detoxify library. Automatically detect if cuda/gpu device is available
+TORCH_DEVICE=auto