Fix some docstrings.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 authors = ["Jimmy Cuadra <jimmy@jimmycuadra.com>"]
-description = "Opaque identifiers for Matrix."
+description = "Resource identifiers for Matrix."
 documentation = "http://ruma.github.io/ruma-identifiers/ruma_identifiers"
 homepage = "https://github.com/ruma/ruma-identifiers"
 keywords = ["matrix", "matrix.org", "chat", "messaging", "ruma"]

README.md

@@ -1,6 +1,6 @@
 # ruma-identifiers
 
-**ruma-identifiers** contains types for [Matrix](https://matrix.org/) opaque identifiers, such as user IDs, room IDs, and room aliases.
+**ruma-identifiers** contains types for [Matrix](https://matrix.org/) identifiers for events, rooms, room aliases, and users.
 
 ## License
 

src/lib.rs

@@ -1,5 +1,5 @@
-//! Crate **ruma_identifiers** contains types for [Matrix](https://matrix.org/) opaque identifiers,
+//! Crate **ruma_identifiers** contains types for [Matrix](https://matrix.org/) identifiers
-//! such as user IDs, room IDs, and room aliases.
+//! for events, rooms, room aliases, and users.
 
 #![deny(missing_docs)]
 
@@ -28,12 +28,14 @@ lazy_static! {
         Regex::new(r"\A[a-z0-9._=-]+\z").expect("Failed to create user localpart regex.");
 }
 
-/// An error encountered when trying to parse an invalid user ID string.
+/// An error encountered when trying to parse an invalid ID string.
 #[derive(Debug, PartialEq)]
 pub enum Error {
     /// The ID's localpart contains invalid characters.
+    ///
+    /// Only relevant for user IDs.
     InvalidCharacters,
-    /// The domain part of the user ID string was not a valid IP address or DNS name.
+    /// The domain part of the the ID string is not a valid IP address or DNS name.
     InvalidHost,
     /// The ID exceeds 255 bytes.
     MaximumLengthExceeded,