Add support for the new machines in Stardew Valley 1.3:

• auto-grabber;
• garden pots.

I'm not sure whether garden pots should be automated, and it's unclear how they should be. Should Automate only harvest their crops? Will players expect them to be watered and replanted too? I'll leave those unautomated for now.

Auto-grabbers are automated in the upcoming Automate 1.10-beta.2.