We cannot use any of the uppy mixins or core code, because
the code there is not shared with the wizard, and to move
it all to discourse-common would be a task almost equal
difficulty to taking the ring to Mordor.
Therefore, we can just use the uppy vendor libraries in the
wizard, and do a quick-n-dirty version of the uppy upload
code for the wizard-field-image uploader.
We rely on yarn workspaces so we don't want people using npm in the repo by accident.
Also updated the required node version to 12+.
~~Not sure about the min yarn version – the latest one could be missing in various CI-like envs, so I might change it yet.~~
Downgraded yarn to ">= 1.21.1" (the oldest of "current" versions, tagged "legacy")
This is to help with the migration to Ember CLI. In the current running
version of Discourse everything should be the same as before, just with
a few extra files that are not used. However, using Ember CLI this can
be installed as an Ember addon.
Co-Authored-By: Jarek Radosz <jradosz@gmail.com>
