Update vimrc: add 'goyo.vim' plugin

Signed-off-by: Michael LeCompte <michaelslec98@gmail.com>
Update vimrc: add 'Goyo' autocmd

Signed-off-by: Michael LeCompte <michaelslec98@gmail.com>
Update vimrc: add Goyo mapping

Signed-off-by: Michael LeCompte <michaelslec98@gmail.com>
Update vimrc: shorten big comment length to 72 columns

Signed-off-by: Michael LeCompte <michaelslec98@gmail.com>
Update vimrc: change mapping to <leader>g
Update vimrc: remove gitcommit FileType from Goyo autocmd
Merge branch 'testing-goyo' into dev