Update docs: fix style issue in update guide
<div class="box-right">
<nav>
<a href="index.html">Home</a>
- <a href="documentation.html" class="current">Documentation</a>
+ <a href="documentation.html">Documentation</a>
<a href="features.html">Features</a>
<a href="https://github.com/Col-E/Recaf">Github</a>
</nav>
