Update docs/changes.txt to reflect changes related to RFC 3629

docs/changes.txt

@@ -22,7 +22,6 @@
 - Added hash-mode: bcrypt(sha256($pass))
 - Added hash-mode: md5(md5($salt).md5(md5($pass)))
 
-
 ##
 ## Performance
 ##
@@ -49,6 +48,7 @@
 - Modules: Added support for non-zero IVs for -m 6800 (Lastpass). Also added `tools/lastpass2hashcat.py`
 - Status Code: Add specific return code for self-test fail (-11)
 - SCRYPT: Increase buffer sizes in module for hash mode 8900 to allow longer SCRYPT digests
+- Unicode: Update UTF8 to UTF16 conversion to match RFC 3629
 
 * changes v6.2.5 -> v6.2.6