Move lsp config to local file structure

.config/nvim/lsp/hhvm.lua

@@ -0,0 +1,14 @@
+---@brief
+---
+--- Language server for programs written in Hack
+--- https://hhvm.com/
+--- https://github.com/facebook/hhvm
+--- See below for how to setup HHVM & typechecker:
+--- https://docs.hhvm.com/hhvm/getting-started/getting-started
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'hh_client', 'lsp' },
+  filetypes = { 'php', 'hack' },
+  root_markers = { '.hhconfig' },
+}