doc: add examples and notes to http server.close et al

Add examples to `http` server.close, server.closeAllConnections,
server.closeIdleConnections. Also add notes about usage for both
server.close*Connections libraries.

PR-URL: #49091
Reviewed-By: Paolo Insogna <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Marco Ippolito <[email protected]>

Author: mmarchini

doc/api/http.md

@@ -1679,13 +1679,59 @@ connected to this server which are not sending a request or waiting for
 a response.
 See [`net.Server.close()`][].
 
+```js
+const http = require('node:http');
+
+const server = http.createServer({ keepAliveTimeout: 60000 }, (req, res) => {
+  res.writeHead(200, { 'Content-Type': 'application/json' });
+  res.end(JSON.stringify({
+    data: 'Hello World!',
+  }));
+});
+
+server.listen(8000);
+// Close the server after 10 seconds
+setTimeout(() => {
+  server.close(() => {
+    console.log('server on port 8000 closed successfully');
+  });
+}, 10000);
+```
+
 ### `server.closeAllConnections()`
 
 <!-- YAML
 added: v18.2.0
 -->
 
-Closes all connections connected to this server.
+Closes all connections connected to this server, including active connections
+connected to this server which are sending a request or waiting for a response.
+
+> This is a forceful way of closing all connections and should be used with
+> caution. Whenever using this in conjunction with `server.close`, calling this
+> _after_ `server.close` is recommended as to avoid race conditions where new
+> connections are created between a call to this and a call to `server.close`.
+
+```js
+const http = require('node:http');
+
+const server = http.createServer({ keepAliveTimeout: 60000 }, (req, res) => {
+  res.writeHead(200, { 'Content-Type': 'application/json' });
+  res.end(JSON.stringify({
+    data: 'Hello World!',
+  }));
+});
+
+server.listen(8000);
+// Close the server after 10 seconds
+setTimeout(() => {
+  server.close(() => {
+    console.log('server on port 8000 closed successfully');
+  });
+  // Closes all connections, ensuring the server closes successfully
+  server.closeAllConnections();
+}, 10000);
+```
 
 ### `server.closeIdleConnections()`
 
@@ -1696,6 +1742,37 @@ added: v18.2.0
 Closes all connections connected to this server which are not sending a request
 or waiting for a response.
 
+> Starting with Node.js 19.0.0, there's no need for calling this method in
+> conjunction with `server.close` to reap `keep-alive` connections. Using it
+> won't cause any harm though, and it can be useful to ensure backwards
+> compatibility for libraries and applications that need to support versions
+> older than 19.0.0. Whenever using this in conjunction with `server.close`,
+> calling this _after_ `server.close` is recommended as to avoid race
+> conditions where new connections are created between a call to this and a
+> call to `server.close`.
+
+```js
+const http = require('node:http');
+
+const server = http.createServer({ keepAliveTimeout: 60000 }, (req, res) => {
+  res.writeHead(200, { 'Content-Type': 'application/json' });
+  res.end(JSON.stringify({
+    data: 'Hello World!',
+  }));
+});
+
+server.listen(8000);
+// Close the server after 10 seconds
+setTimeout(() => {
+  server.close(() => {
+    console.log('server on port 8000 closed successfully');
+  });
+  // Closes idle connections, such as keep-alive connections. Server will close
+  // once remaining active connections are terminated
+  server.closeIdleConnections();
+}, 10000);
+```
+
 ### `server.headersTimeout`
 
 <!-- YAML