feat: add icon

Author: felixfbecker

package.json

@@ -3,6 +3,7 @@
   "name": "code-ownership",
   "publisher": "sourcegraph",
   "description": "See code owners of the current file",
+  "icon": "data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>🔐</text></svg>",
   "license": "Apache",
   "repository": {
     "type": "git",