Ensure text remains visible during webfont load (#269)

* Ensure text remains visible during webfont load

As specified here: https://web.dev/font-display/?utm_source=lighthouse&utm_medium=unknown#google-fonts

* Update CONTRIBUTORS.md

CONTRIBUTORS.md

@@ -57,3 +57,4 @@
 - [Michael Lynch](https://github.com/mtlynch)
 - [FIGBERT](https://figbert.com/)
 - [Yash Mehrotra](https://yashmehrotra.com)
+- [Paolo Mainardi](https://paolomainardi.com)

layouts/_default/baseof.html

@@ -21,7 +21,7 @@
       <link rel="canonical" href="{{ .Permalink }}">
     {{ end }}
 
-    <link href="https://fonts.googleapis.com/css?family=Lato:400,700%7CMerriweather:300,700%7CSource+Code+Pro:400,700" rel="stylesheet">
+    <link href="https://fonts.googleapis.com/css?family=Lato:400,700%7CMerriweather:300,700%7CSource+Code+Pro:400,700&display=swap" rel="stylesheet">
     <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.11.2/css/all.css" integrity="sha384-KA6wR/X5RY4zFAHpv/CnoG2UW1uogYfdnP67Uv7eULvTveboZJg0qUpmJZb5VqzN" crossorigin="anonymous" />
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/normalize/8.0.1/normalize.min.css" integrity="sha256-l85OmPOjvil/SOvVt3HnSSjzF1TUMyT9eV0c2BzEGzU=" crossorigin="anonymous" />