Vi IMproved

Using NetRW as a file tree.
From this post
tldr:

let g:netrw_banner = 0 " Hide the banner
let g:netrw_browse_split = 3 " Open in new tab
let g:netrw_winsize = 25 " Size
let g:netrw_liststyle = 3 " Show files in tree form	

Improving the :grep command to work similar to how ack.vim works
See the full gist, it explains everything
final snippet:

function! Grep(...)
	return system(join([&grepprg] + [expandcmd(join(a:000, ' '))], ' '))
endfunction
command! -nargs=+ -complete=file_in_path -bar Grep  cgetexpr Grep(<f-args>)
command! -nargs=+ -complete=file_in_path -bar LGrep lgetexpr Grep(<f-args>)
augroup quickfix
	autocmd!
	autocmd QuickFixCmdPost cgetexpr cwindow
	autocmd QuickFixCmdPost lgetexpr lwindow
augroup END	

If and only if you indent with tabs, vim can bestow upon you a slick tab line:
set list lcs=tab:\│\ " There is a space here :)

This is a pretty neat capability I did not know vim had,
By the power of an included plugin, You can run :TOhtml to convert the entire current file to a HTML with all of vim's
syntax highlighted goodness,
And you can script it! Like so:

lang="$2"
f=$(mktemp)
echo "$0" | head -n -1 | nvim -n --headless \
	+"let g:html_no_progress = 0"\
	+"let g:html_ignore_folding = 0"\
	+'let g:html_prevent_copy = "fn"'\
	+"set ft=$1"\
	+"runtime! syntax/2html.vim"\
	+"wq! $f"\
	+"q!" - 1> /dev/null	

• ✏ This is now used to generate code syntax highlighting for this site. - Turns out it was way too slow
  

I find vim's help pages annoying to navigate since by default, its difficult to navigate between sections, this fixes it:
au FileType help,man nnoremap <buffer> <CR> <C-]>
This makes it so hitting enter in a help buffer will try to just to the currently selected word
(the world the cursor is on.)
Here are some more nice shortcuts: https://vim.fandom.com/wiki/Learn_to_use_help#Simplify_help_navigation

Using vim as a man pager

There are lots of ways to do it (documented here but
the simplest way I found is to simple alias man, like so in your shell configuration file:

man () {
	nvim +"Man $2 $1" +"only"
}	

• This has some issues like files like ./local.man but I do not often use this so its not a problem for me.
  

Here are a few useful gists on the topic:
https://gist.github.com/romainl/2f748f0c0079769e9532924b117f9252

https://gist.github.com/romainl/ce55ce6fdc1659c5fbc0f4224fd6ad29

What I did to get shellcheck to work:

• Setup an autocommand to set the compiler to shellcheck -f gcc for any shell files
  
• Used https://github.com/mh21/errormarker.vim to get ALE like markings
  
• From error marker's readme: let &errorformat="%f:%l:%c: %t%*[^:]:%m,%f:%l: %t%*[^:]:%m," . &errorformat
  
• Made vim run :make on file write.
  

As much as I hate to link a luke smith video, this one actually explains stuff so here you go: https://www.youtube.com/watch?v=ez1XBUqbS68
But basically:

• Enable spell checking with :set spell
  
• Add words to the white list with zg
  
• Add words to the black list with zug
  
• Go through the suggest corrections with z= while your cursor is over misspelled word.
  

local spell_complete = vim.api.nvim_replace_termcodes('<C-x><C-k>', true, true, true)
local M = {}
function M.spell()
	if vim.opt.spell
	and (vim.fn.pumvisible() == 0)
	and ((vim.v.char >= 'a' and vim.v.char <= 'z')
	or (vim.v.char >= 'A' and vim.v.char <= 'Z')) then
		vim.fn.feedkeys(spell_complete, 'n')
	end
end
function M.setup_spell()
	vim.opt.spell = true
	vim.cmd [[
	autocmd InsertCharPre * lua require('auto').spell() " You'll need to change this
	]]
end

-- And this too:
vim.cmd [[ au FileType markdown,html lua require('auto').setup_spell() ]]

return M