Add entrypoint for vendor js file, add bootstrap js

- Now we have 2 entry files and 2 bundles
- The vendor file houses code that is less likely to change, 3rd party libraries
- The main file has all of our app code

package.json

@@ -17,7 +17,9 @@
     "file-loader": "^3.0.1",
     "html-loader": "^0.5.5",
     "html-webpack-plugin": "^3.2.0",
+    "jquery": "^3.3.1",
     "node-sass": "^4.11.0",
+    "popper.js": "^1.14.7",
     "sass-loader": "^7.1.0",
     "style-loader": "^0.23.1",
     "webpack": "^4.29.6",