feat: audit logs

[StarpTech]

Motivation and Context

• Tests or benchmark included
• Documentation is changed or added on https://app.gitbook.com/
• PR title must follow conventional-commit-standard

[JivusAyrus]

We should have an audit log when the subscription is upgraded right?

One more doubt, what is the diff between subscription.created and subscription.activated

[StarpTech]

@JivusAyrus good points. I missed the event.

one more doubt, what is the diff between subscription.created and subscription.activated

created when the user creates a subscription for the first time. Activated once stripe reports that the subscription is active.

[thisisnithin]

LGTM