doc: fix broken TLS security level example

The example under "Setting security levels" does not run. The client
sets `maxVersion: 'TLSv1'` while its `minVersion` stays at the
`tls.DEFAULT_MIN_VERSION` default of `'TLSv1.2'`, so no version overlaps
and the connection fails with ERR_SSL_NO_PROTOCOLS_AVAILABLE. Setting
the client's `minVersion` is not enough on its own: the handshake then
fails with an alert 40, because `createServer` is given no key or
certificate and the server has no shared cipher.

Set `minVersion` on the client, add the key and certificate placeholders
and the openssl recipe that the other sections using them already carry,
pass the server certificate as the client's `ca`, and use port 8000 like
the rest of the file. The section now runs from an empty directory and
prints "Client connected with protocol: TLSv1".

Signed-off-by: Julian Soreavis <julian.soreavis@gmail.com>
PR-URL: #65391
Fixes: #60569
Refs: #60571
Reviewed-By: Tim Perry <pimterry@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: soreavis

doc/api/tls.md

@@ -468,35 +468,64 @@ to set the security level to 0 while using the default OpenSSL cipher list, you
 
 ```mjs
 import { createServer, connect } from 'node:tls';
-const port = 443;
+import { readFileSync } from 'node:fs';
+const port = 8000;
 
-createServer({ ciphers: 'DEFAULT@SECLEVEL=0', minVersion: 'TLSv1' }, function(socket) {
+createServer({
+  key: readFileSync('server-key.pem'),
+  cert: readFileSync('server-cert.pem'),
+  ciphers: 'DEFAULT@SECLEVEL=0',
+  minVersion: 'TLSv1',
+}, function(socket) {
   console.log('Client connected with protocol:', socket.getProtocol());
   socket.end();
   this.close();
 })
 .listen(port, () => {
-  connect(port, { ciphers: 'DEFAULT@SECLEVEL=0', maxVersion: 'TLSv1' });
+  connect(port, {
+    ciphers: 'DEFAULT@SECLEVEL=0',
+    minVersion: 'TLSv1',
+    maxVersion: 'TLSv1',
+    ca: [ readFileSync('server-cert.pem') ],
+  });
 });
 ```
 
 ```cjs
 const { createServer, connect } = require('node:tls');
-const port = 443;
+const { readFileSync } = require('node:fs');
+const port = 8000;
 
-createServer({ ciphers: 'DEFAULT@SECLEVEL=0', minVersion: 'TLSv1' }, function(socket) {
+createServer({
+  key: readFileSync('server-key.pem'),
+  cert: readFileSync('server-cert.pem'),
+  ciphers: 'DEFAULT@SECLEVEL=0',
+  minVersion: 'TLSv1',
+}, function(socket) {
   console.log('Client connected with protocol:', socket.getProtocol());
   socket.end();
   this.close();
 })
 .listen(port, () => {
-  connect(port, { ciphers: 'DEFAULT@SECLEVEL=0', maxVersion: 'TLSv1' });
+  connect(port, {
+    ciphers: 'DEFAULT@SECLEVEL=0',
+    minVersion: 'TLSv1',
+    maxVersion: 'TLSv1',
+    ca: [ readFileSync('server-cert.pem') ],
+  });
 });
 ```
 
 This approach sets the security level to 0, allowing the use of legacy features while still
 leveraging the default OpenSSL ciphers.
 
+To generate the certificate and key for this example, run:
+
+```bash
+openssl req -x509 -newkey rsa:2048 -nodes -sha256 -subj '/CN=localhost' \
+  -keyout server-key.pem -out server-cert.pem
+```
+
 ### Using [`--tls-cipher-list`][]
 
 You can also set the security level and ciphers from the command line using the