Move lsp config to local file structure

.config/nvim/lsp/rescriptls.lua

@@ -0,0 +1,58 @@
+---@brief
+---
+--- https://github.com/rescript-lang/rescript-vscode/tree/master/server
+---
+--- ReScript Language Server can be installed via npm:
+--- ```sh
+--- npm install -g @rescript/language-server
+--- ```
+---
+--- See [package.json](https://github.com/rescript-lang/rescript-vscode/blob/master/package.json#L139)
+--- for init_options supported.
+---
+--- For example, in order to disable the `inlayHints` option:
+--- ```lua
+--- vim.lsp.config('rescriptls', {
+---   settings = {
+---     rescript = {
+---       settings = {
+---         inlayHints = { enable = false },
+---       },
+---     },
+---   })
+--- }
+--- ```
+---
+--- Detect file changes: While using @rescript/language-server >= 1.63.0 you have to detect file changes by registering the didChangeWatchedFiles hook.
+--- ```lua
+--- capabilities = {
+---     workspace = {
+---         didChangeWatchedFiles = {
+---             dynamicRegistration = true,
+---         },
+---     },
+--- }
+--- ```
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'rescript-language-server', '--stdio' },
+  filetypes = { 'rescript' },
+  root_markers = { 'bsconfig.json', 'rescript.json', '.git' },
+  settings = {},
+  init_options = {
+    extensionConfiguration = {
+      -- buggy, prompts much too often, superseded by incrementalTypechecking, below
+      askToStartBuild = false,
+
+      allowBuiltInFormatter = true, -- lower latency
+      incrementalTypechecking = { -- removes the need for external build process
+        enabled = true,
+        acrossFiles = true,
+      },
+      cache = { projectConfig = { enabled = true } }, -- speed up latency dramatically
+      codeLens = true,
+      inlayHints = { enable = true },
+    },
+  },
+}