Line numbers in "padding" buffers

I couldn't find any reference to this issue elsewhere so I decided to make one.

I've recently installed Goyo in nvim 0.3.1 and I love it but I cannot seem to figure out how to disable line numbering in the "padding" buffers that are created around the active buffer.

This is the relevant configuration from my `init.vim` file:
```vim
" GOYO + Limelight Config
"-----------------------------------------------------------------
let g:goyo_width = 140
let g:goyo_linenr=0
function! s:goyo_enter()
call s:disable_autonumber()
set nocursorcolumn nocursorline
set nonumber
let g:undotree_CustomUndotreeCmd = 'leftabove vertical 32 new'
let g:undotree_CustomDiffpanelCmd = 'belowright 12 new'
Limelight
endfunction
function! s:goyo_leave()
call s:enable_autonumber()
set cursorcolumn cursorline
set number
unlet g:undotree_CustomUndotreeCmd
unlet g:undotree_CustomDiffpanelCmd
Limelight!
endfunction
augroup rn_distraction_free
au!
autocmd! User GoyoEnter nested call goyo_enter()
autocmd! User GoyoLeave nested call goyo_leave()
augroup END

" hybrid (auto-switching) line numbers - see https://jeffkreeftmeijer.com/vim-number/
function! s:disable_autonumber()
au! rn_autonumber
endfunction
function! s:enable_autonumber()
augroup rn_autonumber
au!
au BufEnter,FocusGained,InsertLeave * set norelativenumber
au BufLeave,FocusLost,InsertEnter * set relativenumber
augroup END
endfunction
set number
call s:enable_autonumber()
```
Does anybody have any idea how I can resolve (i.e. disable all line numbers when in :Goyo mode)?

No source file or test is named. Reproduce the report with the supplied init.vim configuration and inspect Goyo's handling of the padding buffers and Vim line-number options. Done means entering :Goyo leaves line numbers disabled in all padding buffers while preserving the expected behavior in the active buffer.

Written by the indexing model from the issue text.