Typography: Use Source Code Pro for the monospace font

Grab variable woff2 files from GitHub.

https://github.com/adobe-fonts/source-code-pro/

assets/css/010_typography.css

@@ -11,10 +11,26 @@
  # FONTS
  ********/
 
+@font-face{
+  font-family: source-code-pro;
+  font-weight: 200 900;
+  font-style: normal;
+  font-stretch: normal;
+  src: url({{ (resources.Get "fonts/sourceCodePro-variable.woff2").Permalink }});
+}
+
+@font-face{
+  font-family: source-code-pro;
+  font-weight: 200 900;
+  font-style: italic;
+  font-stretch: normal;
+  src: url({{ (resources.Get "fonts/sourceCodePro-italic-variable.woff2").Permalink }});
+}
+
 :root {
   --font-family-sans: system-ui, Arial, sans-serif;
   --font-family-serif: Georgia, serif;
-  --font-family-monospace: monospace;
+  --font-family-monospace: source-code-pro, monospace;
 
   --font-family-body: var(--font-family-sans);
   --font-family-heading: var(--font-family-monospace);