Allow the user to customize the structure of the Message

[Romaixn]

Currently, the process function takes a message parameter of type any. I would like the user to be able to create their own custom structure and use it directly in the process function.

For example, in the example instead of passing message any, passing message Message :

type Message struct {
	ID     int `json:"id"`
	Number int `json:"number"`
}

func processMessage(message Message, err chan error) {
}

[sudhir512kj]

@Romaixn label this issue with hacktoberfest-accepted, I would like to work on this

[Romaixn]

I assigned you the ticket, feel free to submit a PR 👍🏻