Changed Grid Size to 50%

This allows 1 order of magnitude of more towers to built. Will require
PathFinding tweaks as the search space is pretty damn large now.
However, smaller size gives us a few substantial benefits, 1: Model
quality can be substantially worse due to lower resolution. 2: Mazing is
much more effective, 3: Is much closer to the source material (WC3 & SC2
wintermaul wars), so the different in aesthetic is less jarring. Might
scale from 5 to 6.77 later if 5 is too small (Before this commit,
dimensions of grid was 10x10 per cell, 50x50 cells, this commit
introduces 5x5 per cell, 100x100 cells, considering 6.77x6.77 per cell).