docs: add elysia-oauth2-resource-server

This plugin provides standard OAuth2 resource server functionality. Compared to @elysiajs/jwt, this package focuses solely on validating tokens from external OAuth2 providers against JWKS endpoints.

This enables secure integration with identity providers like Auth0, Okta, Ory, and custom OAuth2 servers. It is meant to be used in implementing protected APIs in microservice architectures where authentication is handled by a separate authorization server, i.e. an auth gateway.

Author: ap-1

docs/plugins/overview.md

@@ -59,6 +59,7 @@ This is to ensure developers end up with a performant web server they intend to
 -   [Vite Plugin SSR](https://github.com/timnghg/elysia-vite-plugin-ssr) - Vite SSR plugin using Elysia server
 -   [OAuth 2.0](https://github.com/kravetsone/elysia-oauth2) - a plugin for [OAuth 2.0](https://en.wikipedia.org/wiki/OAuth) Authorization Flow with more than **42** providers and **type-safety**!
 -   [OAuth2](https://github.com/bogeychan/elysia-oauth2) - handle OAuth 2.0 authorization code flow
+-   [OAuth2 Resource Server](https://github.com/ap-1/elysia-oauth2-resource-server) - a plugin for validating JWT tokens from OAuth2 providers against JWKS endpoints with support for issuer, audience, and scope verification
 -   [Elysia OpenID Client](https://github.com/macropygia/elysia-openid-client) - OpenID client based on [openid-client](https://github.com/panva/node-openid-client)
 -   [Rate Limit](https://github.com/rayriffy/elysia-rate-limit) - simple, lightweight rate limiter
 -   [Logysia](https://github.com/tristanisham/logysia) - classic logging middleware