BREAKING CHANGE: Remove custom transport support, use Payload's email config

- Removed custom transport configuration from plugin
- Plugin now requires Payload email to be configured
- Simplified setup by relying on Payload's email adapter
- Updated README with new configuration requirements
- Bump version to 0.2.0 (breaking change)

Users must now configure email in their Payload config using an email adapter
like @payloadcms/email-nodemailer instead of configuring transport in the plugin.

src/types/index.ts

@@ -1,6 +1,5 @@
 import { Payload } from 'payload'
 import type { CollectionConfig, RichTextField } from 'payload'
-import { Transporter } from 'nodemailer'
 
 // JSON value type that matches Payload's JSON field type
 export type JSONValue = string | number | boolean | { [k: string]: unknown } | unknown[] | null | undefined
@@ -70,7 +69,6 @@ export interface MailingPluginConfig {
   }
   defaultFrom?: string
   defaultFromName?: string
-  transport?: Transporter | MailingTransportConfig
   queue?: string
   retryAttempts?: number
   retryDelay?: number
@@ -82,17 +80,6 @@ export interface MailingPluginConfig {
   initOrder?: 'before' | 'after'
 }
 
-export interface MailingTransportConfig {
-  host: string
-  port: number
-  secure?: boolean
-  auth?: {
-    user: string
-    pass: string
-  }
-}
-
-
 export interface QueuedEmail {
   id: string
   template?: string | null