Update routing.md (#1397) (#1481)

Author: chrisdel101

en/guide/routing.md

@@ -158,7 +158,7 @@ app.get(/.*fly$/, (req, res) => {
 })
 ```
 
-<h3 id="route-parameters">Route parameters</h3>
+<h2 id="route-parameters">Route parameters</h2>
 
 Route parameters are named URL segments that are used to capture the values specified at their position in the URL. The captured values are populated in the `req.params` object, with the name of the route parameter specified in the path as their respective keys.
 
@@ -280,17 +280,17 @@ app.get('/example/d', [cb0, cb1], (req, res, next) => {
 
 The methods on the response object (`res`) in the following table can send a response to the client, and terminate the request-response cycle. If none of these methods are called from a route handler, the client request will be left hanging.
 
-| Method               | Description
-|----------------------|--------------------------------------
-| [res.download()](/{{ page.lang }}/4x/api.html#res.download)   | Prompt a file to be downloaded.
-| [res.end()](/{{ page.lang }}/4x/api.html#res.end)        | End the response process.
-| [res.json()](/{{ page.lang }}/4x/api.html#res.json)       | Send a JSON response.
-| [res.jsonp()](/{{ page.lang }}/4x/api.html#res.jsonp)      | Send a JSON response with JSONP support.
-| [res.redirect()](/{{ page.lang }}/4x/api.html#res.redirect)   | Redirect a request.
-| [res.render()](/{{ page.lang }}/4x/api.html#res.render)     | Render a view template.
-| [res.send()](/{{ page.lang }}/4x/api.html#res.send)       | Send a response of various types.
-| [res.sendFile()](/{{ page.lang }}/4x/api.html#res.sendFile)     | Send a file as an octet stream.
-| [res.sendStatus()](/{{ page.lang }}/4x/api.html#res.sendStatus) | Set the response status code and send its string representation as the response body.
+| Method                                                          | Description                                                                           |
+| --------------------------------------------------------------- | ------------------------------------------------------------------------------------- |
+| [res.download()](/{{ page.lang }}/4x/api.html#res.download)     | Prompt a file to be downloaded.                                                       |
+| [res.end()](/{{ page.lang }}/4x/api.html#res.end)               | End the response process.                                                             |
+| [res.json()](/{{ page.lang }}/4x/api.html#res.json)             | Send a JSON response.                                                                 |
+| [res.jsonp()](/{{ page.lang }}/4x/api.html#res.jsonp)           | Send a JSON response with JSONP support.                                              |
+| [res.redirect()](/{{ page.lang }}/4x/api.html#res.redirect)     | Redirect a request.                                                                   |
+| [res.render()](/{{ page.lang }}/4x/api.html#res.render)         | Render a view template.                                                               |
+| [res.send()](/{{ page.lang }}/4x/api.html#res.send)             | Send a response of various types.                                                     |
+| [res.sendFile()](/{{ page.lang }}/4x/api.html#res.sendFile)     | Send a file as an octet stream.                                                       |
+| [res.sendStatus()](/{{ page.lang }}/4x/api.html#res.sendStatus) | Set the response status code and send its string representation as the response body. |
 
 <h2 id="app-route">app.route()</h2>