Format fix html files from 2019

2019/poikola/index.html

@@ -472,12 +472,18 @@ file <code>poikola.pdf</code>. This requires the
 <a href="https://en.wikipedia.org/wiki/PdfTeX">pdfTeX</a> tool.</p>
 <h3 id="what-this-entry-does">What this entry does:</h3>
 <p>An old wise man mumbled to me:</p>
-<pre><code>    Implement a program, which can calculate SHA-3 checksum for a file --</code></pre>
+<blockquote>
+<p>Implement a program, which can calculate SHA-3 checksum for a file –</p>
+</blockquote>
 <p>I thought it was easy, but the wizard didn’t stop yet:</p>
-<pre><code>    and primes and Fibonacci numbers.</code></pre>
+<blockquote>
+<p>and primes and Fibonacci numbers.</p>
+</blockquote>
 <p>Still easy. But the <a href="https://www.glyphweb.com/arda/g/gandalf.html">Gandalf the
 Grey</a> impersonator was not ready:</p>
-<pre><code>    But use only `main()`, and do not use `math.h` nor predefined stuff at all.</code></pre>
+<blockquote>
+<p>But use only <code>main()</code>, and do not use <code>math.h</code> nor predefined stuff at all.</p>
+</blockquote>
 <p>But wait, there are more rules: This work should reflect the extraordinary mind
 of Matti Nykänen, the all-time best <a href="https://en.wikipedia.org/wiki/Matti_Nyk%C3%A4nen">ski
 jumper</a> and <a href="http://telefinn.blogspot.com/2011/11/matti-nykanen-quotes.html">amateur