Mistral readme (#994)

* Mistral: print the generated text.

* Add mistral to the readmes.

candle-examples/examples/mistral/README.md

@@ -0,0 +1,37 @@
+# candle-mistral: 7b LLM with Apache 2.0 license weights
+
+- [Announcement Blog Post](https://mistral.ai/news/announcing-mistral-7b/).
+- [Model card](https://huggingface.co/mistralai/Mistral-7B-v0.1) on the
+  HuggingFace Hub.
+
+```bash
+$ cargo run --example mistral --release --features cuda -- --prompt 'Write helloworld code in Rust' --sample-len 150
+
+Generated text:
+Write helloworld code in Rust
+=============================
+
+This is a simple example of how to write "Hello, world!" program in Rust.
+
+## Compile and run
+
+``bash
+$ cargo build --release
+   Compiling hello-world v0.1.0 (/home/user/rust/hello-world)
+    Finished release [optimized] target(s) in 0.26s
+$ ./target/release/hello-world
+Hello, world!
+``
+
+## Source code
+
+``rust
+fn main() {
+    println!("Hello, world!");
+}
+``
+
+## License
+
+This example is released under the terms
+```