Simplify the font families

Just use the system fonts. Nothing special yet.

assets/css/010_typography.css

@@ -17,31 +17,13 @@
  # FONTS
  ********/
 
-@import url("https://use.typekit.net/fji8aoy.css");
-
-{{ with resources.Get "fonts/merriweather.woff2" -}}
-  @font-face {
-    font-family: "merriweather";
-    src: url("{{ .Permalink }}");
-  }
-{{- end }}
-
-{{ with resources.Get "fonts/merriweather-italic.woff2" -}}
-  @font-face {
-    font-family: "merriweather";
-    font-style: italic;
-    src: url("{{ .Permalink }}");
-  }
-{{- end }}
-
 :root {
-  /* --font-family-heading: "rockwell", serif; */
   --font-family-sans: system-ui, Arial, sans-serif;
-  --font-family-serif: "merriweather", Georgia, serif;
+  --font-family-serif: Georgia, serif;
-  --font-family-monospace: "source-code-pro", monospace;
+  --font-family-monospace: monospace;
 
   --font-family-body: var(--font-family-sans);
-  --font-family-heading: var(--font-family-serif);
+  --font-family-heading: var(--font-family-monospace);
 
   --text-base-size: 125%;
   --text-base: {{ $base }}{{ $unit }};
@@ -77,12 +59,10 @@ h1, h2, h3, h4, h5, h6 {
 
 h1 {
   font-size: var(--text-xxl);
-  letter-spacing: 0.05em;
 }
 
 h2 {
   font-size: var(--text-xl);
-  letter-spacing: 0.03em;
 }
 
 h3 {
@@ -113,14 +93,13 @@ sup {
 
 .title {
   font-size: var(--text-xxl);
-  letter-spacing: 0.05em;
 }
 
 .subtitle {
   font-weight: lighter;
+  font-family: var(--font-family-serif);
 }
 
-figcaption,
 small,
 .text--small
 {