Update the guide to include more and accurate information about wheat planting

[scssquatch]

• Adds a blurb about putting down the sprinklers before Summer 28 so the wheat can finish by Fall 2
• Corrects the price of wheat seeds from 5 to 10g
• Adds a blurb about shipping enough items to buy the pumpkin seeds for Fall 2

[scssquatch]

Also it might be helpful to put a couple reminders at the beginning of Spring and Summer to remind people to get exclusive fish/flowers for the community center bundles. The flowers you can make in the greenhouse at least, but things like pufferfish/Sunfish you have to wait until the following spring/summer if you miss them. (or get lucky with the travelling merchant)

[Zamiell]

can you submit a pr