feat: support resend templates

[IdrisHanafi]

What's new?

Adding support for Resend templates, i.e.:

curl -X POST 'https://api.resend.com/emails' \
  -H 'Authorization: Bearer re_xxxxxxxxx' \
  -H 'Content-Type: application/json' \
  -d $'{
    "from": "Acme <onboarding@resend.dev>",
    "to": "delivered@resend.dev",
    "template": {
      "id": "order-confirmation",
      "variables": {
        "PRODUCT": "Vintage Macintosh",
        "PRICE": 499
      }
    }
}'

Testing

mix test

And some manual testing by:

$ iex -S mix
> client = Resend.client(api_key: "re_your_api_key_here")
> Resend.Emails.send(client, %{
  from: "Your Name <[email protected]>",
  subject: "test subject",
  to: "[email protected]",
  template: %{
    id: "your-template-id",
    variables: %{
      YOUR_VARIABLE_NAME: "Your Variable Value"
    }
  }
})

[itzmidinesh]

Thanks for working on the template support! We're currently evaluating Resend as an alternative and templates are critical for our use case.

Are there plans to merge this into the library?