nvim: ftplugin: Drop cabal format and Haskell key mappings

We never really used these Haskell key mappings and the cabal
format support is not something we care about now (86be7efd5).

nvim/.config/nvim/after/ftplugin/cabal.lua

@@ -1 +0,0 @@
-vim.bo.commentstring = "-- %s"

nvim/.config/nvim/after/ftplugin/cabal/cabalfmt.vim

@@ -1,55 +0,0 @@
-" Taken from https://github.com/sdiehl/vim-cabalfmt
-
-if !exists("g:cabalfmt_command")
-  let g:cabalfmt_command = "cabal-fmt"
-endif
-
-if !exists("g:cabalfmt_options")
-  let g:cabalfmt_options = [""]
-endif
-
-function! s:OverwriteBuffer(output)
-  if &modifiable
-    let l:curw = winsaveview()
-    try | silent undojoin | catch | endtry
-    let splitted = split(a:output, '\n')
-    if line('$') > len(splitted)
-      execute len(splitted) .',$delete'
-    endif
-    call setline(1, splitted)
-    call winrestview(l:curw)
-  else
-    echom "Cannot write to non-modifiable buffer"
-  endif
-endfunction
-
-function! s:RunCabal()
-  if exists("bufname")
-    let output = system(g:cabalfmt_command . " " . join(g:cabalfmt_options, ' ') . " " . bufname("%"))
-  else
-    let stdin = join(getline(1, '$'), "\n")
-    let output = system(g:cabalfmt_command . " " . join(g:cabalfmt_options, ' '), stdin)
-  endif
-  if v:shell_error != 0
-    echom output
-  else
-    call s:OverwriteBuffer(output)
-    if exists("bufname")
-      write
-    endif
-  endif
-endfunction
-
-function! s:CabalHaskell()
-  if executable(g:cabalfmt_command)
-    call s:RunCabal()
-  else
-    echom "cabal-fmt executable not found"
-  endif
-endfunction
-
-function! RunCabal()
-  call s:CabalHaskell()
-endfunction
-
-nnoremap <buffer> <silent> gq :call RunCabal()<CR>

nvim/.config/nvim/after/ftplugin/haskell.vim

@@ -1,29 +0,0 @@
-" Taken from https://github.com/danidiaz/miscellany/blob/master/linux/.vim/ftplugin/haskell/movements.vim
-" Next top-level type signature
-nnoremap <script> <silent> ]f /^\w[^:=$]*\(::\\|\n\s*::\)<CR>
-" Previous top-level type signature
-nnoremap <script> <silent> [f ?^\w[^:=$]*::\(::\\|\n\s*::\)<CR>
-" Next type signature
-nnoremap <script> <silent> ]l /^\s*\w[^:=$]*\(::\\|\n\s*::\)<CR>
-" Previous type signature
-nnoremap <script> <silent> [l ?^\s*\w[^:=$]*\(::\\|\n\s*::\)<CR>
-" Next data declaration
-nnoremap <script> <silent> ]t /^\(data \\|newtype \\|type \\|class\)<CR>
-" Previous data declaration
-nnoremap <script> <silent> [t ?^\(data \\|newtype \\|type \\|class\)<CR>
-" Beginning of imports
-nnoremap <script> <silent> [i gg/^import <CR>z<CR>
-" End of imports
-nnoremap <script> <silent> [I G?^import <CR>zb
-" Beginning of module exports
-nnoremap <script> <silent> [m gg/^module <CR>z<CR>
-" End of module exports (wonky)
-nnoremap <script> <silent> [M gg/^\s*)\s*where\s*$<CR>zb<CR>
-" Next named chunk of documentation
-" https://www.haskell.org/haddock/doc/html/ch03s05.html
-nnoremap <script> <silent> ]n /^-- \$\w\+<CR>z<CR>
-" Previous named chunk of documentation
-nnoremap <script> <silent> [n ?^-- \$\w\+<CR>z<CR>
-
-" Disable vim-matchup
-autocmd! BufEnter <buffer> :NoMatchParen