Standardize and materialize 500, 404, and 403 pages

.gitignore

 target
 .settings
 .project
-.classpath
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+.classpath
+.idea/
+myuw-error-valve/myuw-error-valve.iml
+myuw-root-webapp/ROOT.iml
+myuw-root-webapp/src/main/webapp/bucky-sad.png
+node_modules/
+package.json
+root-parent.iml

README.md

@@ -2,4 +2,9 @@
 
 [![build status](https://git.doit.wisc.edu/ci/projects/15/status.png?ref=master)](https://git.doit.wisc.edu/ci/projects/15?ref=master)
 
-This is the root context of myuw. It is just here to serve up some static html pages for 500 and 400 level errors.
\ No newline at end of file
+This is the root context of myuw. It is just here to serve up some static html pages for 500 and 400 level errors.
+
+### Development
+
+From the root directory, run `npm start`. The web app will run at [http://localhost:8080](http://localhost:8080) and will 
+show the 404 page by default. 
\ No newline at end of file