Add some option (if, event and lazy)#2

Add some options. - On-demand loading vim event ```vim Pack 'ntpeters/vim-better-whitespace', { 'event': 'CursorHold' } Pack 'neoclide/coc.nvim', { 'event': ['InsertEnter', 'CursorMoved'] } ``` - Only valid if conditions are met ```vim Pack 'nvim-treesitter/nvim-treesitter', { 'if': has('nvim') } ``` - After VimEnter, the timer_start function packadd plugins ```vim Pack 'andymass/vim-matchup', { 'type': 'lazy' } ``` - Add `g:plugpac_cfg_path` option. ```vim let g:plugpac_cfg_path = '~/.vim/rc' ```