home: vim: configure 'null-ls' for 'haskell'

home/vim/after/ftplugin/haskell.vim

@@ -1,6 +1,14 @@
 " Create the `b:undo_ftplugin` variable if it doesn't exist
 call ftplugined#check_undo_ft()
 
+" Set-up LSP, linters, formatters
+lua << EOF
+local null_ls = require("null-ls")
+null_ls.register({
+    null_ls.builtins.formatting.brittany,
+})
+EOF
+
 " Use a small indentation value on Haskell files
 setlocal shiftwidth=2
 let b:undo_ftplugin.='|setlocal shiftwidth<'