add dev/files to gitignore
add dev/files to gitignore

hyesun03/k-board,cjh5414/kboard,hyesun03/k-board,guswnsxodlf/k-board,guswnsxodlf/k-board,cjh5414/kboard,kboard/kboard,kboard/kboard,cjh5414/kboard,hyesun03/k-board,kboard/kboard,darjeeling/k-board,guswnsxodlf/k-board