Content: SDG graphic and DPG cert on Contributing page

**Which module(s) and week(s) does this change affect?**
Content: Guides > Contributing

**What is the work that needs to be done?**

I want a graphic like IOM Eire have https://ireland.iom.int/

I'm talking to them about something else and we should really have something like this, along with our DPG cert

**Why is this work important to do?**

Marketing, baby

**Additional context**

**Who might need to know about this change?**