vscode: add icon & set to preview

Author: sbdchd

squawk-vscode/icon.png

@@ -6,12 +6,20 @@
     "type": "git",
     "url": "https://github.com/sbdchd/squawk.git"
   },
+  "icon": "icon.png",
   "author": "Squawk Team & Contributors",
   "license": "(Apache-2.0 OR MIT)",
-  "version": "0.0.1",
+  "version": "0.0.2",
   "engines": {
     "vscode": "^1.101.0"
   },
+  "preview": true,
+  "keywords": [
+    "postgres",
+    "postgreSQL",
+    "linter",
+    "sql"
+  ],
   "categories": [
     "Programming Languages",
     "Linters"