Say that the CLI's Init counts engine creation twice (LiteRT-LM #4057)

The CLI's printed Init includes both Init Total and the phases inside it. One sentence, no number changed.

README.md

@@ -84,6 +84,8 @@ Two honest caveats, both measured rather than assumed:
 | GPU (Metal) | 3673 tok/s | 144.6 tok/s | 0.077 s | 2.8 s |
 | CPU | 427 tok/s | 33.3 tok/s | 0.63 s | 6.4 s |
 
+Init is the `Init time` the CLI prints; that value includes both `Init Total` and the phases inside it, so it counts engine creation twice ([LiteRT-LM #4057](https://github.com/google-ai-edge/LiteRT-LM/issues/4057)).
+
 Pixel 8a (Tensor G3), `litert_lm_advanced_main` from the v0.16.0 kit, 205-token prompt, `--benchmark`:
 
 | Backend | Prefill (205) | Decode | TTFT |