Changed TypeScript target and fixed outdated comment

Author: abartho

tsconfig.json

@@ -2,7 +2,7 @@
   "compilerOptions": {
     /* Visit https://aka.ms/tsconfig.json to read more about this file */
 
-    "target": "ES2020",                       // Electron 11 is based on Chrome 87, which supports ES2020
+    "target": "ES2019",                       // Electron 12 is based on Chrome 89, which supports ES2019
                                               // https://kangax.github.io/compat-table/es2016plus/
     "module": "commonjs",
     "esModuleInterop": true,                  // Enables emit interoperability between CommonJS and ES