v3.0.0

Implements changes based on feedback from https://discourse.purescript.org/t/rfc-eventemitter-bindings-and-http2-bindings/3584/8

Breaking Changes:

• changes the EventHandle suffix from Handle to just H (e.g. closeHandle -> closeH)
• reorders the emitter arg to be last in all listener-adding functions to enable eventEmitter # on eventNameH \args -> ... style of coding
• renames functions to drop the Subscribe part. Now, on returns a callback that removes the listener. If this is not desired, then on_ just adds the listener with no way to remove it via callback.

Other Improvements:

• updating docs
• adding EventHandleX up to 7 args
• making spago -x test.dhall install actually work by writing the test.dhall file slightly differently
• defined JsSymbol and wrote bindings for Symbol.for and Symbol.keyFor, and a Show instance