Changed the configuration for sumneko_lua to the recommended configuration by nvim-lspconfig

after/plugin/lsp.lua

@@ -8,12 +8,26 @@ lsp.ensure_installed({
   'rust_analyzer',
 })
 
--- Fix Undefined global 'vim'
+-- Set up sumneko_lua according to the
+-- recommended settings by nvim-lspconfig
 lsp.configure('sumneko_lua', {
     settings = {
         Lua = {
+            runtime = {
+                -- Tell the language server which version of Lua you're using (most likely LuaJIT in the case of Neovim)
+                version = "LuaJIT"
+            },
             diagnostics = {
+                -- Get the langauge server to recognize the `vim` global
                 globals = { 'vim' }
+            },
+            workspace = {
+                -- Make the server aware of Neovim runtime files
+                library = vim.api.nvim_get_runtime_file("", true)
+            },
+            -- Do not send telemetry data containing a randomized but unique identifier
+            telemetry = {
+                enable = false
             }
         }
     }