hoauth2-2.6.0: README.org

* Introduction

Lightweight Haskell binding for

- [The OAuth 2.0 Authorization Framework](https://datatracker.ietf.org/doc/html/rfc6749)
  - If the provider does implement [OIDC spec](https://openid.net/specs/openid-connect-core-1_0.html),
    ID Token would also be included in token response (see `OAuth2Token`).
- [The OAuth 2.0 Authorization Framework: Bearer Token Usage](https://www.rfc-editor.org/rfc/rfc6750)