How can I permanently install my (toy) WebExtension without having to publish it via Mozilla Addons (AMO), when my extension is just a small group of CSS hacks not meant to be published.
The other option, installing it only permanently would be cumbersome to do everytime I need the extension.
EDIT:
To add further input, the page I've linked to says
- Zip up your extension's files Edit
At this point your extension will consist of a directory containing a manifest.json and any other files it needs - scripts, icons, HTML documents, and so on. You'll need to zip these into a single file for uploading to AMO.
One trick is that the ZIP file must be a ZIP of the extension's files themselves, not of the containing directory.
and also
Packaged extensions in Firefox are called "XPI files", which are just ZIP files with a different extension.
You don't have to use the XPI extension when uploading to AMO.
In about:addons you can install from file, but whatever way I try to package my extension I get:
even after observing and trying the quoted passage above.
The temporary installation works fine.