added meaning of colors in the grid#1482

lokesh-beingzero wants to merge 1 commit intokenkoooo:masterkenkoooo/AtCoderProblems:masterfrom

lokesh-beingzero:document-color-meaning-in-problems-pagelokesh-beingzero/AtCoderProblems:document-color-meaning-in-problems-pageCopy head branch name to clipboard