The following Vim script (VimL) function can be used to make Vim open the documentation of the word under the cursor in a new tab for various languages and tools such as Vim help (:help), Python (Pydoc), Markdown (sdcv dictionary), man pages (Vim’s built-in ‘:Man’), and Ansible (ansible-doc).

The VimL function is also extensible, meaning that you can adapt it to work with any other documentation tool. By default, the key mapping upper-case “K” can be used to open the documentation for the word under the cursor in a new tab.

" Language: Vim script
" Author: James Cherti
" License: MIT
" Description: Vim: open help/documentation in a new tab 
"              (Vim script, Python, Markdown, man pages, Ansible...).
"              Press upper-case K to open help for the word under the cursor.
" URL: https://www.jamescherti.com/vim-open-help-documentation-in-a-new-tab/

function! TabHelp(word) abort
  let l:cmd = ''

  let l:tabhelpprg = get(b:, 'tabhelpprg', '')
  if l:tabhelpprg ==# ''
    normal! K
    return
  endif

  if l:tabhelpprg[0] ==# ':'
    if stridx(l:tabhelpprg, '%s') ==# -1
      execute l:tabhelpprg
    else
      execute printf(l:tabhelpprg, fnameescape(a:word))
    endif
    return
  else
    let l:cmd = 'silent read! '
    if stridx(l:tabhelpprg, '%s') ==# -1
      let l:cmd .= l:tabhelpprg
    else
      let l:cmd .= printf(l:tabhelpprg, shellescape(a:word))
    endif
  endif

  execute 'silent tabnew help:' . fnameescape(a:word)

  setlocal modifiable
  silent normal! ggdG
  silent normal! 1Gdd
  if l:cmd !=# ''
    execute l:cmd
  endif
  silent normal! gg0
  setlocal nomodifiable
  setlocal noswapfile
  setlocal nowrap
  setlocal nonumber
  setlocal nomodified
  setlocal buftype=nofile
  setlocal bufhidden=delete
  if exists('&relativenumber')
    setlocal norelativenumber
  endif
  if exists('&signcolumn')
    setlocal signcolumn=no
  endif
  setlocal nofoldenable
  setlocal foldcolumn=0
endfunction

augroup TabHelp
  autocmd!
  autocmd FileType vim let b:tabhelpprg = ':tab help %s'
  autocmd FileType sh,zsh,csh if ! exists(':Man') | runtime ftplugin/man.vim | endif | let b:tabhelpprg = ':tab Man %s'
  autocmd FileType yaml.ansible if executable('ansible-doc') | let b:tabhelpprg = 'ansible-doc %s' | endif
  autocmd FileType markdown if executable('sdcv') | let b:tabhelpprg = 'sdcv %s' | endif
  autocmd FileType vim,sh,zsh,csh,yaml.ansible,markdown nnoremap <silent> <buffer> K :call TabHelp(expand('<cword>'))<CR>
augroup ENDCode language: Vim Script (vim)