Update README.md

Signed-off-by: declark1 <[email protected]>

Author: declark1

README.md

@@ -28,7 +28,65 @@ mocktail is a **minimal** crate for mocking HTTP and gRPC servers in Rust, with
     mocktail = { git = "https://github.com/IBM/mocktail.git", version = "0.2.4-alpha" }
     ```
 
-2. For now, see [examples](/mocktail-tests/tests/examples) in the `mocktail-tests` crate. Additional documentation coming soon.
+2. Basic usage example:
+    ```rust
+    use mocktail::prelude::*;
+
+    #[tokio::test]
+    async fn test_example() -> Result<(), Box<dyn std::error::Error>> {
+        // Create a mock set
+        let mut mocks = MockSet::new();
+
+        // Build a mock that returns a "hello world!" response
+        // to POST requests to the /hello endpoint with the text "world"
+        // in the body.
+        mocks.mock(|when, then| {
+            when.post().path("/hello").text("world");
+            then.text("hello world!");
+        });
+
+        // Create and start a mock server
+        let mut server = MockServer::new("example").with_mocks(mocks);
+        server.start().await?;
+
+        // Create a client
+        let client = reqwest::Client::builder().http2_prior_knowledge().build()?;
+
+        // Send a request that matches the mock created above
+        let response = client
+            .post(server.url("/hello"))
+            .body("world")
+            .send()
+            .await?;
+        assert_eq!(response.status(), http::StatusCode::OK);
+        let body = response.text().await?;
+        assert_eq!(body, "hello world!");
+
+        // Send a request that doesn't match a mock
+        let response = client.get(server.url("/nope")).send().await?;
+        assert_eq!(response.status(), http::StatusCode::NOT_FOUND);
+
+        // Mocks can also be registered to the server directly
+        // Register a mock that will match the request above that returned 404
+        server.mock(|when, then| {
+            when.get().path("/nope");
+            then.text("yep!");
+        });
+
+        // Send the request again, it should now match
+        let response = client.get(server.url("/nope")).send().await?;
+        assert_eq!(response.status(), http::StatusCode::OK);
+        let body = response.text().await?;
+        assert_eq!(body, "yep!");
+
+        // Mocks can be cleared from the server, enabling server reuse
+        server.mocks.clear();
+
+        Ok(())
+    }
+    ```
+
+3. See the [book](https://ibm.github.io/mocktail/) and [examples](/mocktail-tests/tests/examples) in the `mocktail-tests` crate.
 
 # Examples
 See [examples](/mocktail-tests/tests/examples) in the `mocktail-tests` crate.