It's not yet available to use.
Maybe you need to make it early access so steam users see it and can participate in leaving feed back. Such approach quite popular in steam nowadays.
At current state (when there is no actual game in steam), steam users with much less chance know about game and even less find this link in itch.io to try out :)
Btw, are you same developers (or connected to) who made Stardew Valley or just inspired by it?