Add support for sending invitations to users

[cmackenzie1]

I could only find invitations for Organizations but not for individual users.

• https://clerk.com/docs/reference/backend-api/tag/Invitations
• https://clerk.com/docs/custom-flows/invitations#creating-invitations

[gkats]

Can I work on this?

@luigimorel Yes please!! 🙏

We welcome contributions, let me know if you need any help or guidelines.

[jeremyhcho]

Any updates on this?

[luigimorel]

sorry, @jeremyhcho got busy. will finish up later in the day.

[luigimorel]

If this could get assigned to another person.
As I can't really find the time to do open source stuff at the moment.

[gkats]

Perhaps you're aware of that already, but we already support Invitation related API operations in v2 of the Clerk Go SDK.

https://pkg.go.dev/github.com/clerk/clerk-sdk-go/v2/invitation

Would switching to v2 be an option for you?