guide: Add a char example to the supported types section

examples/guide-supported-types-examples/char.js

@@ -0,0 +1,9 @@
+import {
+  take_char_by_value,
+  return_char,
+} from './guide_supported_types_examples';
+
+take_char_by_value('a');
+
+let c = return_char();
+console.log(typeof c); // "string"

examples/guide-supported-types-examples/src/char.rs

@@ -0,0 +1,9 @@
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+pub fn take_char_by_value(x: char) {}
+
+#[wasm_bindgen]
+pub fn return_char() -> char {
+    '🚀'
+}

examples/guide-supported-types-examples/src/lib.rs

@@ -7,3 +7,4 @@ pub mod imported_types;
 pub mod exported_types;
 pub mod str;
 pub mod string;
+pub mod char;

guide/src/reference/types.md

@@ -91,6 +91,18 @@ garbage-collected heap and the Wasm linear memory with `TextDecoder` and
 |:---:|:---:|:---:|:---:|:---:|:---:|:---:|
 | Yes | No | No | Yes | No | No | A JavaScript string value |
 
+### Example Rust Usage
+
+```rust
+{{#include ../../../examples/guide-supported-types-examples/src/char.rs}}
+```
+
+### Example JavaScript Usage
+
+```js
+{{#include ../../../examples/guide-supported-types-examples/char.js}}
+```
+
 ## `bool`
 
 | `T` parameter | `&T` parameter | `&mut T` parameter | `T` return value | `Option<T>` parameter | `Option<T>` return value | JavaScript representation |