Move lsp config to local file structure

.config/nvim/lsp/koka.lua

@@ -0,0 +1,11 @@
+---@brief
+---
+--- https://koka-lang.github.io/koka/doc/index.html
+--- Koka is a functional programming language with effect types and handlers.
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'koka', '--language-server', '--lsstdio' },
+  filetypes = { 'koka' },
+  root_markers = { '.git' },
+}