Mention mbstring dependency

Author: Gert-dev

index.html

@@ -320,6 +320,7 @@ <h2 id="what-do-i-need">Awesome! What do I need?</h2>
         <ul>
             <li><em>PHP 5.6 or higher</em> &mdash; The code you're actually writing can be anything ranging from PHP 5.2 up to (and including) PHP 7.1.</li>
             <li><em>php-sqlite and SQLite >= 3.7.11</em> &mdash; Required as back end for the indexing database.</li>
+            <li><em>php-mbstring</em> &mdash; Required as source code can contain Unicode characters in strings or comments.</li>
             <li><em><a href="https://github.com/danielbrodin/atom-project-manager">atom-project-manager</a></em> &mdash; Fire up your active project and go to <em>Packages &rarr; PHP Integrator &rarr; Set Up Current Project</em> (or use the command palette).</li>
             <li><em>Proper docblocks and type hinting</em> - See <a href="https://github.com/php-integrator/core/wiki">our wiki</a> for more information.</li>
         </ul>