Update style.less (#4)

* Update style.less

In chrome and safari the main-page content is not shown in the center of the page.
Adding a

display:flex

to the body-styles in the css-file fixes this problem.

* Update style.less

static/less/style.less

@@ -16,6 +16,7 @@ html {
 }
 
 body {
+  display:flex;
   color: @fg-color;
   background-color: @bg-color;
 	font-family: 'Fira Mono', monospace;