📝 Add context document

Author: aisk

docs/context.md

@@ -0,0 +1,26 @@
+---
+title: Context
+nav_order: 4
+---
+
+# Context
+
+Vox's `Context` object is a wrapper around the standard `context.Context` from the Go standard library. It provides a way to pass data between middlewares and to control the execution of the middleware chain.
+
+## App
+
+The `App` field is a pointer to the `vox.Application` instance. This can be used to access the application's configuration or other properties.
+
+## Next
+
+The `Next` function is used to call the next middleware in the chain. It's the middleware's responsibility to call the `Next` function. If a middleware does not call `Next`, the execution of the middleware chain will be terminated.
+
+Here is an example of a simple logging middleware that uses the `Context` object to pass data to the next middleware:
+
+```go
+func Logger(ctx *vox.Context, req *vox.Request, res *vox.Response) {
+    start := time.Now()
+    ctx.Next()
+    log.Printf("%s %s %v", req.Method, req.URL.Path, time.Since(start))
+}
+```