Move lsp config to local file structure

.config/nvim/lsp/pli.lua

@@ -0,0 +1,12 @@
+---@brief
+---
+--- `pli_language_server` is a language server for the PL/I language used on IBM SystemZ mainframes.
+---
+--- To learn how to configure the PL/I language server, see the [PL/I Language Support documentation](https://github.com/zowe/zowe-pli-language-support).
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'pli_language_server' },
+  filetypes = { 'pli' },
+  root_markers = { '.pliplugin' },
+}