Fix events documentation

[bukacdan]

Describe the bug
In official documentation, section Events, there's a reference to full list of global events in events.ts. However, it seems like this information is outdated and these events are not emitted anymore (see #1349).

To Reproduce
Steps to reproduce the behavior:

1. Go to https://gridjs.io/docs/examples/event-handler

Expected behavior
Documentation should be updated to reflect the current functionality. Ready event can be observed with solution from #1349 (comment). Would be nice to mention and explain this solution and suggest how other global events can be observed.

Desktop (please complete the following information):

• OS: MacOS
• Browser: chrome
• Version: 6.1.1.