Add to Extension Manager

[leolost2605]

Hey 👋,

I put together a little flatpak app called Extension Manager which basically knows a list of extensions and tells the user to add a curated PPA from which they can easily install/uninstall extensions for elementary OS. It's currently submitted for appcenter review at elementary/appcenter-reviews#495. I'm not sure whether it will go through though but I guess there's always still flathub :)

Now what this issue is about:
I'd like to provide your extension in Extension Manager. It currently already is, I uploaded it to the PPA and if you want you can try it by installing the app, following instructions and it should show up under Top Panel Indicators.
Is this okay with you or should I remove it? There will be no additional work for you :)
(Also to do this I had to fix debian packaging and will open a PR for that)