I like web components, the simpler the better, so I like what I see but having a strong OCD about syntax I just want to propose the use of <Button ... instead of <elena-button ...

It's just a matter of using a regex [1] and making your syntax more palatable

Regardless, kudos for the release

* const componentRegex = /<%[ ]+([A-Z][a-zA-Z0-9])([^%]?)%>/g;