MAINT: Add repository to package.json

package.json

@@ -2,6 +2,10 @@
   "name": "@indiscale/ckeditor5-complexitywiki-plugins",
   "version": "0.0.1",
   "description": "CaosDB's wiki plugins for CKEditor 5.",
+  "repository": {
+    "type": "git",
+    "url": "https://gitlab.indiscale.com/caosdb/src/ckeditor5-complexitywiki-plugins"
+  },
   "keywords": [
     "ckeditor",
     "ckeditor5",