Added docs for Context Storage Middleware (#463)

.vitepress/config.ts

@@ -155,6 +155,7 @@ const sidebars = (): DefaultTheme.SidebarItem[] => [
       { text: 'Cache', link: '/docs/middleware/builtin/cache' },
       { text: 'Combine', link: '/docs/middleware/builtin/combine' },
       { text: 'Compress', link: '/docs/middleware/builtin/compress' },
+      { text: 'Context Storage', link: '/docs/middleware/builtin/context-storage' },
       { text: 'CORS', link: '/docs/middleware/builtin/cors' },
       {
         text: 'CSRF Protection',

docs/index.md

@@ -159,6 +159,7 @@ Out of the box, Hono provides middleware and helpers for:
 - [Body Limit](/docs/middleware/builtin/body-limit)
 - [Cache](/docs/middleware/builtin/cache)
 - [Compress](/docs/middleware/builtin/compress)
+- [Context Storage](/docs/middleware/builtin/context-storage)
 - [Cookie](/docs/helpers/cookie)
 - [CORS](/docs/middleware/builtin/cors)
 - [ETag](/docs/middleware/builtin/etag)

docs/middleware/builtin/context-storage.md

@@ -0,0 +1,30 @@
+# Context Storage Middleware
+
+The Context Storage Middleware stores the Hono `Context` in the `AsyncLocalStorage`, to make it globally accessible. 
+
+## Import
+
+```ts
+import { Hono } from 'hono'
+import { contextStorage, getContext } from 'hono/context-storage'
+```
+
+## Usage
+
+```ts
+type Env = {
+  Variables: {
+    message: string
+  }
+}
+
+const app = new Hono<Env>()
+
+app.use(contextStorage())
+
+app.get('/', (c) => c.text(getMessage())
+
+const getMessage = () => {
+  return getContext<Env>().var.message
+}
+```