Update HISTORY.md

Reformat and link to wiki.

Author: ericf

HISTORY.md

@@ -1 +1,8 @@
-For changelogs, please see the HISTORY.md files in each component directory (e.g. `/src/anim/HISTORY.md`).
+YUI's change history is available in two formats:
+
+* Per-Release on the Wiki:
+  * [Current Release](https://github.com/yui/yui3/wiki#current-release)
+  * [Past Releases](https://github.com/yui/yui3/wiki#past-releases)
+* Per-Component in each component's `HISTORY.md` 
+  (e.g. [`/src/app/HISTORY.md`](https://github.com/yui/yui3/blob/master/src/app/HISTORY.md)).
+