Easy way to check build number on KhanAcademy

It would be cool if the commit version of the editor would show if you added "...&version=show" to the url. Then advanced users could tell if the new features are on the editor yet.

No file or test is named. Start by tracing how the editor parses URL parameters and where its current commit or build version is available, then determine how the version value is displayed when the URL includes "version=show". Done means advanced users can open that URL and see the editor's commit version.

Written by the indexing model from the issue text.