Update README.md

ShayBox · web-flow · commit f465a6f1a1bc · 2021-03-14T08:57:52.000-04:00
diff --git a/README.md b/README.md
@@ -6,4 +6,5 @@ Pull requests are welcome
 
 Known Issues:
   - macOS FN modifier key (CircuitPython limitation)
+  - F20+ (CircuitPython limitation)
   - Missing Modes and Mode switching (PR Welcome)
