Write documentation for Event Listeners component

[favour-chibueze]

We need to write documentation on the Event Listeners component.

https://devdocs.mautic.org/en/5.x/plugins/event_listeners.html

[ifeoluwafavour]

Hello @favour-chibueze Please I would like to work on this issue Are these the event listeners to be documented? https://github.com/mautic/mautic/tree/5.x/app%2Fbundles%2FPluginBundle%2FEventListener

[favour-chibueze]

Sure.. see the old documentation too for the event listeners.

[ifeoluwafavour]

Okay. Thank you!