add changelog date and improve formatting

CHANGELOG.md

@@ -1,17 +1,17 @@
-## 0.1.1 ()
+## 0.1.1 (November 26, 2015)
 
 Features:
 
-  - support periodic updates: https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/1
-  - support limit and sort by (playlist contents should be correct, but ordering may not be): https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/9
-  - show number of matched tracks when editing playlists: https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/6
-  - add explanations for field values: https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/13, https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/12
+  - support periodic updates: [#1](https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/1)
+  - support limit and sort by (playlist contents should be correct, but ordering may not be): [#9](https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/9)
+  - show number of matched tracks when editing playlists: [#6](https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/6)
+  - add explanations for field values: [#13](https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/13), [#12](https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/12)
 
 ## 0.0.1 (November 24, 2015)
 
 First packaged release!
 
 Features:
 
-  - support datetime fields: https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/2
-  - support any/all and subqueries: https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/4
+  - support datetime fields: [#2](https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/2)
+  - support any/all and subqueries: [#4](https://github.com/simon-weber/Autoplaylists-for-Google-Music/issues/4)