When attempting to add this component to a Custom Tab, as per these instructions from Salesforce, the component is not available to add to a tab.
Luckily, the solution is really easy! It just entails adding an additional <target> object within componentName.js-meta.xml. I've tested independently and supplied the change via PR #3 .
References
- Salesforce Docs: Add Lightning Components as Custom Tabs in a Lightning App
- Lightning Web Components Developer Guide: Configure Components for Custom Tabs