crypto: Document the rust Device struct

rust-sdk/src/device.rs

@@ -2,12 +2,22 @@ use std::collections::HashMap;
 
 use matrix_sdk_crypto::Device as InnerDevice;
 
+/// An E2EE capable Matrix device.
 pub struct Device {
+    /// The device owner.
     pub user_id: String,
+    /// The unique ID of the device.
     pub device_id: String,
+    /// The published public identity keys of the devices
+    ///
+    /// A map from the key type (e.g. curve25519) to the base64 encoded key.
     pub keys: HashMap<String, String>,
+    /// The supported algorithms of the device.
     pub algorithms: Vec<String>,
+    /// The human readable name of the device.
     pub display_name: Option<String>,
+    /// A flag indicating if the device has been blocked, blocked devices don't
+    /// receive any room keys from us.
     pub is_blocked: bool,
 }