added automated gradle build support

hi! i grabbed this the other day and have done a small amount of testing with the project (did similar with the archimedes-ships mod, and it seems to be working; only done enough to see that Coca Leaves show up from your mod at this point, so nominally built and working, apparently); also have created a github with the files at playlaughlovelearn/LisasGradleTemplate since i imagine i'm not the only one who pulls mods and builds them and doesn't want to re-invent the wheel every time.

i don't think there are any particularly forge-centric things going on but ForgeGradle pulls MCP and allows for creating the decomp workspace, also. the files that were moved were because gradle's default Java workspace expects the files there, reduced the amount of unknowns i had to figure out before it was working; i don't think it's a terrible lot of work if you prefer to keep your source files at the same spot, i would be happy to look at that if you would like.

anyhow, so figured i would put in a pull request here and archimedes' so you folks could benefit from it, should you care to have this kind of setup. :) <3