* add nginx to load balancing nav menu and fix bullets
* fill out nginx lb guide
* formatting
* change Nginx to NGINX
* add step to verify load balancer config
* update docker image and web app output
* change Nginx to NGINX in main load balancing page
* modify change signal to SIGHUP and add else condition in template stanza to prevent nginx from crashing when no services are available to load balance
* add note about external load balancer
* clarifications and link to reference architecture
