chore: remove CONTRIBUTING.md and update icon image (#162)

* chore: remove CONTRIBUTING.md and update icon image

- Deleted the CONTRIBUTING.md file as it is no longer needed.
- Updated the icon.png file with a new version for better quality.

* chore(package): bump version to 1.2.1

Author: harryisfish

CONTRIBUTING.md

@@ -1,7 +1,7 @@
 {
   "name": "__MSG_extensionName__",
   "displayName": "__MSG_extensionDisplayName__",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "description": "__MSG_extensionDescription__",
   "author": "leaperone",
   "scripts": {