Document ruma-client crate features

crates/ruma-client/src/lib.rs

@@ -69,6 +69,25 @@
 //! }
 //! # ;
 //! ```
+//!
+//! # Crate features
+//!
+//! The following features activate http client types in the [`http_client`] module:
+//!
+//! * `hyper`
+//! * `hyper-native-tls`
+//! * `hyper-rustls`
+//! * `isahc`
+//! * `reqwest` – if you use the `reqwest` library already, activate this feature and configure the
+//!   TLS backend on `reqwest` directly. If you want to use `reqwest` but don't depend on it
+//!   already, use one of the sub-features instead. For details on the meaning of these, see
+//!   [reqwest's documentation](https://docs.rs/reqwest/0.11/reqwest/#optional-features):
+//!   * `reqwest-native-tls`
+//!   * `reqwest-native-tls-alpn`
+//!   * `reqwest-native-tls-vendored`
+//!   * `reqwest-rustls-manual-roots`
+//!   * `reqwest-rustls-webpki-roots`
+//!   * `reqwest-rustls-native-roots`
 
 #![warn(missing_docs)]
 #![cfg_attr(docsrs, feature(doc_cfg))]

crates/ruma/src/lib.rs

@@ -55,6 +55,13 @@
 //! * `events`
 //! * `signatures`
 //!
+//! # `ruma-client` features
+//!
+//! The `client` feature activates [`ruma::client`][client], and `client-ext-client-api` activates
+//! `ruma-client`s `client-api` feature. All other `client-*` features activate the same feature
+//! without the `client-` prefix on `ruma-client`. See the crate's documentation for the effect of
+//! these features.
+//!
 //! If you are viewing this on `docs.rs`, you can have a look at the feature dependencies by
 //! clicking **Feature flags** in the toolbar at the top.