Add docs from gofiber/fiber@3593436

Author: github-actions[bot]

docs/core/client/rest.md

@@ -95,14 +95,22 @@ type Client struct {
 }
 ```
 
- New
+### New
 
 New creates and returns a new Client object.
 
 ```go title="Signature"
 func New() *Client
 ```
 
+### NewWithClient
+
+NewWithClient creates and returns a new Client object from an existing client object.
+
+```go title="Signature"
+func NewWithClient(c *fasthttp.Client) *Client
+```
+
 ## REST Methods
 
 ### Get