Describe the events dispatched by the SSE event in the style of how the HTMX events are documented.

I had copied the section from another event and forgot to update it.

Added EventSource links to the `htmx:sseError` section that I missed in the previous commit.

Also fix the sections on `htmx:sseBeforeMessage` and `htmx:sseMessage`.

Should've read the source code more closely. SMH.