fix: add repository information to package.json

Author: willibrandon

package.json

@@ -4,6 +4,10 @@
   "description": "Syntax highlighting for Serilog message templates and Serilog.Expressions",
   "version": "0.1.0",
   "publisher": "mtlog",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/willibrandon/serilog-syntax-vscode"
+  },
   "engines": {
     "vscode": "^1.104.0"
   },