Updated changelog for 1.0.0 (#668)

Author: awschristou

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 All notable changes to the "aws-vscode-tools" extension will be documented in this file.
 
-## NEXT (Developer Preview)
+## 1.0.0
 
 * A toast greets the user upon launching a new version of the toolkit for the first time which provides a link to a quick start page. This quick start page can be re-accessed through the explorer's context menu. (#610-612)
 * Local Run/Debug now honors MemorySize values from SAM Template file (#509)