Don't mess with number and relative numbers if they both are disabled with ftplugin

[kutsan]

My ~/.vim/ftplugin/markdown.vim file has,

setlocal nonumber
setlocal norelativenumber

and this plugin doesn't respect my own settings and overrides them. So, if user explicitly has set nonumber and norelativenumber this plugin shouldn't override them.

This also potentially will solve the problem with g:relativity_filetype_ignore variable. Instead of blacklisting common buffer names, check their number and relativenumber options first.

PS: I don't use this plugin, I just came to look your code and this is my friendly feedback.

I've been using something like this instead of this plugin, FYI.

augroup togglerelativelinenumbers
	autocmd!
	autocmd InsertEnter,BufLeave,WinLeave,FocusLost *
		\ if &l:number && empty(&buftype) |
			\ setlocal norelativenumber |
		\ endif
	autocmd InsertLeave,BufEnter,WinEnter,FocusGained *
		\ if &l:number && empty(&buftype) |
			\ setlocal relativenumber |
		\ endif
augroup end