Hey! Sorry, grass as a resource isn't fully implemented yet no. It should still technically "work" it just doesn't have a sprite or any way to collect it. I've been very busy with school but I'll try to prioritize that in the next update, thanks!
Although if you would like to experiment with it you can press Ctrl + Tilde (`/~) which will open the console, and then use "cia Grass #" where # is how many you want and it'll add them to all colonists/containers. If you select a specific colonist/container it will add it only to them.