Add a new Guide: Session Timeouts (Client (Browser), Web Server)

[j-paquette]

Create a new guide in the docs/_guides folder, using the same format as _template.md

Title: Session Timeouts (Client (Browser), Web Server)
Content: Explain the TBS Guidelines, but user can search Google on how to do it

Add front matter to this guide, something like this:

---
title: Session Timeouts (Client (Browser), Web Server)
layout: default
category: Development
summary: Add a short description of the guide here.
date: YYYY-MM-DD
---

Add further content here