💄 Use font Fira Code to fix display of Rich panels in docs in Windows (#1653)

docs/css/custom.css

@@ -1,3 +1,11 @@
+/* Fira Code, including characters used by Rich output, like the "heavy right-pointing angle bracket ornament", not included in Google Fonts */
+@import url(https://cdn.jsdelivr.net/npm/firacode@6.2.0/distr/fira_code.css);
+
+/* Override default code font in Material for MkDocs to Fira Code */
+:root {
+    --md-code-font: "Fira Code", monospace;
+}
+
 .termynal-comment {
     color: #4a968f;
     font-style: italic;