Presentation mode with Goyo + vim-markdown

presentation.vim

" https://asciinema.org/a/kE1398clJWRPPhk3lWbtvbanF

" Presentation mode
"
" use <left> and <right> to navigate the slides
"
" https://github.com/plasticboy/vim-markdown Makes folds by sections (among many other things)
" https://github.com/junegunn/goyo.vim Distraction-free writing (and reading) in Vim

function! s:enter_presentation()
    " increase conceal level
    set conceallevel=3
    " open first fold
    normal ggzo
    " add navigation
    " C-n next slide
        " zc - close current fold
        " zj - move to the next
        " zo - and open it
        " [z - move to the start of the current fold
        " j  - move the cursor out of the way
    nnoremap <buffer> <right> zczjzo[z<esc>j
    " C-p previous slide
        " zc - close current fold
        " zk - move to the previous
        " zo - and open it
        " [z - move to the start of the current fold
        " j  - move the cursor out of the way
    nnoremap <buffer> <left> zczkzo[zj
endfunction

function! s:exit_presentation()
    " reset conceal level
    set conceallevel=0
    nunmap <buffer> <left>
    nunmap <buffer> <right>
endfunction

autocmd! User GoyoEnter nested call <SID>enter_presentation()
autocmd! User GoyoLeave nested call <SID>exit_presentation()