fix numbering of markdown list

docs/guides/overlay-dev-guide.rst

@@ -16,17 +16,17 @@ screen. If you need very specific low-level control, those APIs might be the
 right choice for you. However, here are some reasons you might want to implement
 an overlay widget instead:
 
-1. You can draw directly to an existing viewscreen instead of creating an
+#. You can draw directly to an existing viewscreen instead of creating an
     entirely new screen on the viewscreen stack. This allows the original
     viewscreen to continue processing uninterrupted and keybindings bound to
     that viewscreen will continue to function. This was previously only
     achievable by C++ plugins.
 
-1. You'll get a free UI for enabling/disabling your widget and repositioning it
+#. You'll get a free UI for enabling/disabling your widget and repositioning it
     on the screen. Widget state is saved for you and is automatically restored
     when the game is restarted.
 
-1. You don't have to manage the C++ interposing logic yourself and can focus on
+#. You don't have to manage the C++ interposing logic yourself and can focus on
     the business logic, writing purely in Lua if desired.
 
 In general, if you are writing a plugin or script and have anything you'd like