via (https://www.linux.com/learn/tutorials/442438-vim-tips-folding-fun)
zf#jcreates a fold from the cursor down # lines.zf/stringcreates a fold from the cursor to string .zjmoves the cursor to the next fold.zkmoves the cursor to the previous fold.zoopens a fold at the cursor.zOopens all folds at the cursor.zmincreases the foldlevel by one.zMcloses all open folds.