exec demo

Running <!exec git log --oneline -10> in local repo clone:

5dc939a Fix elements that receive a path (e.g. <!layout>/!include>/etc.)
5b783aa Initial work for a <!if> statement (#2)
2b9fef4 Add links to github project and home page
6350529 Separate lexer into its own file
5b83e32 New <!exec> tag (fix #5)
e7c5b61 Update to go 1.26
0a3d170 Add possibility to use different <!layout> depending on the method
fc18bb2 Add LayoutResolver to test <!layout> and <!content>
401b9fb Avoid copyright year in every file
03e0df8 Add <meta name="viewport" ...> to website layout

<!layout /.includes/layout.htex>
<article>
  <h2>exec demo</h2>
  <p>Running <code>&lt;!exec git log --oneline -10&gt;</code>
     in <a href="https://github.com/dacap/htex/commits/main/">local repo clone</a>:</p>
  <pre><code><!exec git log --oneline -10></code></pre>
</article>
<article>
  <code>exec.htex</code> source file:
  <pre><code class="language-html"><!include-escaped exec.htex></code></pre>
</article>