Improve documentation

src/events.rs

@@ -1,3 +1,5 @@
+//! # Events specification
+
 use std::path::PathBuf;
 
 use strum::EnumProperty;
@@ -90,7 +92,7 @@ pub enum Event {
     /// However, for ongoing processes (eg. configure())
     /// or for functions that are expected to fail (eg. dc_continue_key_transfer())
     /// it might be better to delay showing these events until the function has really
-    /// failed (returned false). It should be sufficient to report only the _last_ error
+    /// failed (returned false). It should be sufficient to report only the *last* error
     /// in a messasge box then.
     ///
     /// @return