Prevent code with Ubuntu or Ubuntu Mono font from being uppercased

* Ubuntu or Ubuntu Mono fonts were being uppercased when in combination
  with a font-feature-setting called 'case'.

* Set the font feature settings to for <code> tags to 'normal' so
  that the Ubuntu Mono font is not being uppercased

* Put back in the 'case' font-feature setting for the body

source/css/main.css

@@ -18,7 +18,7 @@ body {
   color: var(--light-color);
   text-rendering: optimizeLegibility;
   -webkit-font-smoothing: antialiased;
-  font-feature-settings: "liga", "tnum", "calt", "zero", "ss01", "locl";
+  font-feature-settings: "liga", "tnum", "case", "calt", "zero", "ss01", "locl";
   -webkit-overflow-scrolling: touch;
   -webkit-text-size-adjust: 100%;
 
@@ -83,6 +83,7 @@ img {
 
 code {
   font-family: Consolas,Monaco,Andale Mono,Ubuntu Mono,monospace;
+  font-feature-settings: normal;
   background: var(--light-background-secondary);
   padding: 1px 6px;
   margin: 0 2px;