More app-friendly event description (#6684)

* More app-friendly event description

* change origin -> owner

* checked all decl_event! and changed decriptions.

* annotated parameter names for remaining events

Author: warfollowsme

src/lib.rs

@@ -230,11 +230,11 @@ decl_event! {
 		<T as Trait>::Balance,
 		<T as Trait>::AssetId,
 	{
-		/// Some assets were issued.
+		/// Some assets were issued. [asset_id, owner, total_supply]
 		Issued(AssetId, AccountId, Balance),
-		/// Some assets were transferred.
+		/// Some assets were transferred. [asset_id, from, to, amount]
 		Transferred(AssetId, AccountId, AccountId, Balance),
-		/// Some assets were destroyed.
+		/// Some assets were destroyed. [asset_id, owner, balance]
 		Destroyed(AssetId, AccountId, Balance),
 	}
 }