Add docs from gofiber/fiber@4e98910

Author: github-actions[bot]

docs/core/middleware/responsetime.md

@@ -0,0 +1,55 @@
+---
+id: responsetime
+---
+
+# ResponseTime
+
+Response time middleware for [Fiber](https://github.com/gofiber/fiber) that measures the time spent handling a request and exposes it via a response header.
+
+## Signatures
+
+```go
+func New(config ...Config) fiber.Handler
+```
+
+## Examples
+
+Import the package:
+
+```go
+import (
+    "github.com/gofiber/fiber/v3"
+    "github.com/gofiber/fiber/v3/middleware/responsetime"
+)
+```
+
+### Default config
+
+```go
+app.Use(responsetime.New())
+```
+
+### Custom header
+
+```go
+app.Use(responsetime.New(responsetime.Config{
+    Header: "X-Elapsed",
+}))
+```
+
+### Skip logic
+
+```go
+app.Use(responsetime.New(responsetime.Config{
+    Next: func(c fiber.Ctx) bool {
+        return c.Path() == "/healthz"
+    },
+}))
+```
+
+## Config
+
+| Property | Type | Description | Default |
+| :------- | :--- | :---------- | :------ |
+| Next | `func(c fiber.Ctx) bool` | Defines a function to skip this middleware when it returns `true`. | `nil` |
+| Header | `string` | Header key used to store the measured response time. If left empty, the default header is used. | `"X-Response-Time"` |

docs/core/whats_new.md

@@ -1244,6 +1244,12 @@ Cache keys are now redacted in logs and error messages by default, and a `Disabl
 The deprecated `Store` and `Key` options have been removed in v3. Use `Storage` and `KeyGenerator` instead.
 :::
 
+### ResponseTime
+
+A new response time middleware measures how long each request takes to process and adds the duration to the response headers.
+By default it writes the elapsed time to `X-Response-Time`, and you can change the header name. A `Next` hook lets you skip
+endpoints such as health checks.
+
 ### CORS
 
 We've made some changes to the CORS middleware to improve its functionality and flexibility. Here's what's new: