Website rebuild

This is something on the backed, so nothing visible change, but for me it's significant as it would enable me to manage the website more easily.

I had created a simple template engine called SWSE (Simple Web-Site Engine) which now drives the Expensinator website.

With SWSE the site components are reusable and everything is simple to maintain. You can see the SWSE documentation here: https://swse.chankov.net in case you are interested.