Move lsp config to local file structure

.config/nvim/lsp/zls.lua

@@ -0,0 +1,12 @@
+---@brief
+--- https://github.com/zigtools/zls
+---
+--- Zig LSP implementation + Zig Language Server
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'zls' },
+  filetypes = { 'zig', 'zir' },
+  root_markers = { 'zls.json', 'build.zig', '.git' },
+  workspace_required = false,
+}