Update navigation links to include .html extension

Author: TorstenDittmann

apps/docs/partials/base.hbs

@@ -13,8 +13,8 @@
 			<nav hx-boost="true" preload="mouseover">
 				<a href="/">launch.css</a>
 				<menu>
-					<li><a href="/install">Install</a></li>
-					<li><a href="/docs">Examples</a></li>
+					<li><a href="/install.html">Install</a></li>
+					<li><a href="/docs.html">Examples</a></li>
 					<li><a role="button" href="https://github.com/torstendittmann/launch-css">GitHub</a></li>
 				</menu>
 			</nav>