A little search through the FAQs shows that renaming a workspace is currently not possible.
I’d like to put it forward as a feature request - there are workarounds, but none offer the simplicity and assurance of a rename (e.g. associated databases remaining intact).
I’ve found myself hacking at an idea under a temporary workspace name for a while, then after fleshing it out somewhat wanting to rename it to something more suitable. Cloning covers many use-cases for this, but not all.