Doc: add Cloudron link to wiki

[ildyria]

Detailed description of the problem

from #164 :

We are trying to provide an update for the Lychee Cloudron app. The current version is 3.1.6 and the new version will be 3.2.8-fixed. Since this is for Cloudron, the built-in updater is disabled, since on Cloudron apps run on a read-only filesystem. For reference, our app packaging code can be found at https://git.cloudron.io/cloudron/lychee-app

Maybe adding a pointer to this in the Wiki would be a nice idea. :)