Created script which can be used to assist in automating dynmap image renders periodically

[kaweepatinn1]

Hello! I wanted to automate rendering the dynmap as I wanted to create a montage for my next upcoming smp. Hence, I created this batch file which can help to do so when paired with something like the windows scheduler.

The batch file creates a directory of the current date and generates the image in the current date folder, naming it the current date and time. Parameters such as colors and sizes can be edited in the second last line of the bat file.

I also added a couple missing things from the README to reflect how the dynmap-assemble returns help messages as of right now.