Change default name case for event names to match documentation

[posva]

What rule do you want to change?

https://eslint.vuejs.org/rules/custom-event-name-casing.html#camelcase

Does this change cause the rule to produce more or fewer warnings?

Same

How will the change be implemented? (New option, new default behavior, etc.)?

Default change

Please provide some example code that this change will affect:

      this.$emit('my-event')
      this.$emit('update:myProp', myProp)

      this.$emit('myEvent')

What does the rule currently do for this code?

Allows the 2 first lines, fails on the last.

What will the rule do after it's changed?

It would do the opposite.

It should inverse the default and enforce camel-cased event names when calling emit() like proposed in docs

Additional context

[ota-meshi]

Thank you for posting this issue.
I didn't know the documentation was updated. I think we need to change the default option for the rule in the next major version.

[FloEdelmann]

For reference, the relevant section in the docs: https://vuejs.org/guide/components/events.html#emitting-and-listening-to-events