README.md: Fix example call to the "simple" binary

Author: Papierkorb

README.md

@@ -38,7 +38,7 @@ cd llama-cpp-rs
 Run the simple example (add `--featues cuda` if you have a cuda gpu)
 
 ```bash
-cargo run --release --bin simple "The way to kill a linux process is" hf-model TheBloke/Llama-2-7B-GGUF llama-2-7b.Q4_K_M.gguf
+cargo run --release --bin simple -- --prompt "The way to kill a linux process is" hf-model TheBloke/Llama-2-7B-GGUF llama-2-7b.Q4_K_M.gguf
 ```
 
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