Update target to ES2020 to match node 14+ (#1048)

Author: kanongil

lib/modules/types.js

@@ -18,7 +18,7 @@ const internals = {
         jsx: Ts.JsxEmit.React,
         lib: ['lib.es2020.d.ts'],
         module: Ts.ModuleKind.CommonJS,
-        target: Ts.ScriptTarget.ES2019,
+        target: Ts.ScriptTarget.ES2020,
         moduleResolution: Ts.ModuleResolutionKind.NodeJs
     },