Set make_event to pub

[dakom]

Would allow external code to define CustomEvents more easily

The detail property would just come through as a JsValue and it's up to the user to deserialize

Currently, only StaticEvent types are supported.

[dakom]

I think this is fixed by #25, at least for now

[dakom]

Renamed the issue since the original idea was to have various macros to make custom events easier. This is now handled via external helpers though it depends on having make_event be pub (see the closed PR for more discussion)