fix style collapse in 'grid.html'

replace css class '.show-grid' to '.ge-show-grid' to escape overlapping styles which are derived from 'docs.min.css'
Merge 99ba89d994f4530e697a413c3b9cbad495407f94 into fafb3b6872d22310e5dff13a19c228ecb98d5af4
Travis build 45