Fix grammar mistake in sample index file

docs/_index.md

@@ -1,5 +1,5 @@
 <p class="lead">
-	<strong>Daux.io</strong> is an documentation generator that uses a simple folder structure and Markdown files to create custom documentation on the fly. It helps you create great looking documentation in a developer friendly way.
+	<strong>Daux.io</strong> is a documentation generator that uses a simple folder structure and Markdown files to create custom documentation on the fly. It helps you create great looking documentation in a developer friendly way.
 </p>
 
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