Enhance Dashboard workshop to include additional concepts

[billg-splunk]

Adding a placeholder for some additional dashboard concepts we might want to introduce

• Dashboard mirrors
• O11y Cloud dashboards in Splunk

[hagen-p]

• Dashboard mirrors works on any org ✅. first delivery
• Dashboard in Splunk will require a Splunk licence... 🧩💰 . Secondary delivery and I will make this an optional module and think how to make this flexible for those who do not have Splunk core/cloud yet