docs(example_block_switch): remove unnecessary file and dependence

Author: freedomlang

examples/block-switcher/package-lock.json

@@ -7,13 +7,10 @@
   "dependencies": {
     "@djsp/atomic-block": "^0.1.0",
     "@djsp/core": "^0.1.0",
-    "@djsp/utils": "^0.1.0",
     "prop-types": "^15.6.1",
     "react": "^16.5.0",
     "react-dom": "^16.2.0",
-    "react-scripts": "^1.1.1",
-    "react-text-selection-popover": "^1.0.3",
-    "styled-components": "^3.4.5"
+    "react-scripts": "^1.1.1"
   },
   "scripts": {
     "start": "react-scripts start",