Add documentation for the Feature Lifecycle Dashboard

Add to our docs info about the new Feature Lifecycle dashboard, which explain how it works and specifically the integration with Code References

Start by locating the existing documentation for the Feature Lifecycle Dashboard and its Code References integration. Read the dashboard material to understand how it works, then add documentation covering both its behavior and that integration; done means a newcomer can understand the dashboard and how Code References connects to it.

Written by the indexing model from the issue text.