adding express starter code

cmsc388b/code_examples/express/install.md

+# Steps to set-up express application locally
+
+```npm install express-generator -g```
+
+run `express --help`
+
+run `express first-express-app --view=pug`
+
+naviagte to our app `cd first-express-app`
+
+and then run `npm install`
+
+for windows run `SET DEBUG=express-locallibrary-tutorial:* & npm start`
+
+for mac/linux run `DEBUG=express-locallibrary-tutorial:* npm start`
+
+As an example let's run it without the debug statements and see the difference.
+
+next execute `npm install --save-dev nodemon`
+
+
+
+
+
+