nvim: after/ftplugin/sh: Drop language server & enable linting on save

Bash language server is written in typescript and we do
not want to keep node, npm or pnpm around for this.

nvim/.config/nvim/after/ftplugin/sh.lua

@@ -1,4 +1,6 @@
-local lsp_utils     = require('lsp-utils')
-local bashls_config = lsp_utils.bashls_config()
-
-vim.lsp.start(bashls_config)
+vim.api.nvim_create_autocmd({ "BufWritePost" }, {
+  buffer   = 0,
+  callback = function()
+    require("lint").try_lint()
+  end,
+})