The MakeCode editor allows the publishing of extensions. These extensions can be loaded into another user's script and used by them. They are really useful for publishing drivers for accessories or other useful pieces of hardware, as well as adding in new software features. There is a published guide to build your own extensions.
We do approve some extensions so that they appear in the extension list (or so that you can search by name), but extensions approved in this way must meet specific requirements around documentation and stability, because it's important that our users have a great experience when learning with the micro:bit. Therefore, initially you may just prefer to put a link to your github extension URL on your blog or web page, and tell people to paste that into the extension search box to access your extension.
If you do still want your extension added to the approved list, please fill in this form.
Once we are satisfied that your extension meets requirements (see this example repo), we will submit a Pull Request to the pxt-microbit GitHub Repository to update the following files with your information:
A member of the team will comment on the Pull Request asking the Makecode team to approve.
Please note we are only able to approve requests for genuine micro:bit related accessories.