Fix readme

README.md

@@ -0,0 +1,46 @@
+# OpenAI API client library for Rust
+
+## Installation:
+Cargo.toml
+```
+[dependencies]
+openai-rs = { git = "https://github.com/dongri/openai-rs" }
+```
+
+## Example:
+```bash
+export OPENAI_API_KEY={YOUR_API}
+```
+
+```rust
+use openai_rs::v1::completion::{self, CompletionRequest};
+use openai_rs::v1::api::Client;
+use std::env;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let client = Client::new(env::var("OPENAI_API_KEY").unwrap().to_string());
+    let req = CompletionRequest {
+        model: completion::GPT3_TEXT_DAVINCI_003.to_string(),
+        prompt: Some(String::from("NFTとは？")),
+        suffix: None,
+        max_tokens: Some(3000),
+        temperature: Some(0.9),
+        top_p: Some(1.0),
+        n: None,
+        stream: None,
+        logprobs: None,
+        echo: None,
+        stop: None,
+        presence_penalty: Some(0.6),
+        frequency_penalty: Some(0.0),
+        best_of: None,
+        logit_bias: None,
+        user: None,
+      };
+    let completion_response = client.completion(req).await?;
+    println!("{:?}", completion_response.choices[0].text);
+
+    Ok(())
+}
+```

examples/completion.rs

@@ -7,7 +7,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let client = Client::new(env::var("OPENAI_API_KEY").unwrap().to_string());
     let req = CompletionRequest {
         model: completion::GPT3_TEXT_DAVINCI_003.to_string(),
-        prompt: Some(String::from("NFTとは何か？")),
+        prompt: Some(String::from("NFTとは？")),
         suffix: None,
         max_tokens: Some(3000),
         temperature: Some(0.9),