show micropython control keys help

Author: hfmanson

components/micropython/help.c

@@ -4,4 +4,11 @@ const char esp32_help_text[] =
     "Welcome to BadgePython!\n"
     "\n"
     "Please visit https://docs.badge.team/ for documentation and a getting started guide.\n"
+    "\n"
+    "Control commands:\n"
+    "  CTRL-A        -- on a blank line, enter raw REPL mode\n"
+    "  CTRL-B        -- on a blank line, enter normal REPL mode\n"
+    "  CTRL-C        -- interrupt a running program\n"
+    "  CTRL-D        -- on a blank line, do a soft reset of the board\n"
+    "  CTRL-E        -- on a blank line, enter paste mode\n"
     "\n";