Document MessageState and fix some typos

src/message.rs

@@ -614,14 +614,44 @@ impl Message {
 #[repr(i32)]
 pub enum MessageState {
     Undefined = 0,
+
+    /// Incoming *fresh* message. Fresh messages are neither noticed
+    /// nor seen and are typically shown in notifications.
     InFresh = 10,
+
+    /// Incoming *noticed* message. E.g. chat opened but message not
+    /// yet read - noticed messages are not counted as unread but did
+    /// not marked as read nor resulted in MDNs.
     InNoticed = 13,
+
+    /// Incoming message, really *seen* by the user. Marked as read on
+    /// IMAP and MDN may be sent.
     InSeen = 16,
+
+    /// For files which need time to be prepared before they can be
+    /// sent, the message enters this state before
+    /// OutPending.
     OutPreparing = 18,
+
+    /// Message saved as draft.
     OutDraft = 19,
+
+    /// The user has pressed the "send" button but the message is not
+    /// yet sent and is pending in some way. Maybe we're offline (no
+    /// checkmark).
     OutPending = 20,
+
+    /// *Unrecoverable* error (*recoverable* errors result in pending
+    /// messages).
     OutFailed = 24,
+
+    /// Outgoing message successfully delivered to server (one
+    /// checkmark). Note, that already delivered messages may get into
+    /// the OutFailed state if we get such a hint from the server.
     OutDelivered = 26,
+
+    /// Outgoing message read by the recipient (two checkmarks; this
+    /// requires goodwill on the receiver's side)
     OutMdnRcvd = 28,
 }