Add a new Guide: ESDC Release Services

[j-paquette]

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

Title: ESDC Release Services
Content: add a link to their sharepoint site

Add front matter to this guide, something like this:

---
title: ESDC Release Services
layout: default
category: ESDC: How We Operate
summary: Add a short description of the guide here.
date: YYYY-MM-DD
---

Add further content here