Move lsp config to local file structure

.config/nvim/lsp/elmls.lua

@@ -0,0 +1,35 @@
+---@brief
+---
+--- https://github.com/elm-tooling/elm-language-server#installation
+---
+--- If you don't want to use Nvim to install it, then you can use:
+--- ```sh
+--- npm install -g elm elm-test elm-format @elm-tooling/elm-language-server
+--- ```
+
+local api = vim.api
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'elm-language-server' },
+  -- TODO(ashkan) if we comment this out, it will allow elmls to operate on elm.json. It seems like it could do that, but no other editor allows it right now.
+  filetypes = { 'elm' },
+  root_dir = function(bufnr, on_dir)
+    local fname = api.nvim_buf_get_name(bufnr)
+    local filetype = vim.bo[bufnr].filetype
+    if filetype == 'elm' or (filetype == 'json' and fname:match 'elm%.json$') then
+      on_dir(vim.fs.root(fname, 'elm.json'))
+      return
+    end
+    on_dir(nil)
+  end,
+  init_options = {
+    elmReviewDiagnostics = 'off', -- 'off' | 'warning' | 'error'
+    skipInstallPackageConfirmation = false,
+    disableElmLSDiagnostics = false,
+    onlyUpdateDiagnosticsOnSave = false,
+  },
+  capabilities = {
+    offsetEncoding = { 'utf-8', 'utf-16' },
+  },
+}