[OB3] [Accelerator] Event Notification doc needs more elaboration

[DinithiDiaz]

Affected OB version:

OB 3.0.0

Affected OB specifications:

Accelerator

Existing pages to be updated:

https://ob.docs.wso2.com/en/latest/learn/event-notification/

Description (Optional):

The Event Creation section needs more elaboration:

• Need to add more content from a developer's perspective.
• Need to doc the info on creating events by invoking a library, etc.

[DinithiDiaz]

Hi @dimuthnc / @AmilaSamith,

Please use this doc issue to share the dev content.

Regards, Dinithi