Add message for current and previous release

Author: tomv564

messages.json

@@ -6,5 +6,7 @@
     "0.3.0": "messages/0.3.0.txt",
     "0.4.0": "messages/0.4.0.txt",
     "0.4.1": "messages/0.4.1.txt",
-    "0.4.2": "messages/0.4.2.txt"
+    "0.4.2": "messages/0.4.2.txt",
+    "0.5.0": "messages/0.5.0.txt",
+    "0.6.0": "messages/0.6.0.txt"
 }

messages/0.6.0.txt

@@ -0,0 +1,12 @@
+=> 0.6.0
+
+Features:
+* Diagnostics counter in status bar (@predagnikolic)
+* Richer extensibility framework
+
+Major bug fixes:
+* Fix completion breakage from servers omitting sortText on some completion items. (@rwols)
+
+Plus many more contributions, all very much appreciated!
+
+See https://github.com/tomv564/LSP/releases/tag/0.6.0 for full update details.