add missing colon makes CocSearch working with which-key (#111)

keys/which-key.vim

@@ -18,7 +18,7 @@ let g:which_key_sep = '→'
 " set timeoutlen=100
 
 " Coc Search & refactor
-nnoremap <leader>? CocSearch <C-R>=expand("<cword>")<CR><CR>
+nnoremap <leader>? :CocSearch <C-R>=expand("<cword>")<CR><CR>
 let g:which_key_map['?'] = 'search word'
 
 " Not a fan of floating windows for this