doc: fix indentation issues in sample code

In preparation for stricter ESLint indentation checking, fix a few
issues in sample code.

Backport-PR-URL: https://github.com/nodejs/node/pull/14835
PR-URL: https://github.com/nodejs/node/pull/13950
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/crypto.md

@@ -684,10 +684,11 @@ const hash = crypto.createHash('sha256');
 
 hash.on('readable', () => {
   const data = hash.read();
-  if (data)
+  if (data) {
     console.log(data.toString('hex'));
     // Prints:
     //   6a2da20943931e9834fc12cfe5bb47bbd9ae43489a30726962b576f4e3993e50
+  }
 });
 
 hash.write('some data to hash');
@@ -767,10 +768,11 @@ const hmac = crypto.createHmac('sha256', 'a secret');
 
 hmac.on('readable', () => {
   const data = hmac.read();
-  if (data)
+  if (data) {
     console.log(data.toString('hex'));
     // Prints:
     //   7fd04df92f636fd450bc841c9418e5825c17f33ad9c87c518115a45971f7f77e
+  }
 });
 
 hmac.write('some data to hash');

doc/guides/writing-tests.md

@@ -25,13 +25,13 @@ Let's analyze this basic test from the Node.js test suite:
 ```javascript
 'use strict';                                                          // 1
 const common = require('../common');                                   // 2
-                                                                       // 3
+
 // This test ensures that the http-parser can handle UTF-8 characters  // 4
 // in the http header.                                                 // 5
-                                                                       // 6
+
 const assert = require('assert');                                      // 7
 const http = require('http');                                          // 8
-                                                                       // 9
+
 const server = http.createServer(common.mustCall((req, res) => {       // 10
   res.end('ok');                                                       // 11
 }));                                                                   // 12