Upgrade Prettier from 1.17 to 2.0.2.

Summary:
This gets us on the latest Prettier 2.x:
https://prettier.io/blog/2020/03/21/2.0.0.html

Notably, this adds support for TypeScript 3.8,
which introduces new syntax, such as `import type`.

Reviewed By: zertosh

Differential Revision: D20636268

fbshipit-source-id: fca5833d003804333a05ba16325bbbe0e06d6c8a

desktop/static/SupportRequestPreload.js

@@ -9,11 +9,11 @@
 
 const {ipcRenderer} = require('electron');
 
-global.sendToHost = (message) => {
+global.sendToHost = message => {
   ipcRenderer.sendToHost(message);
 };
 
-global.setupToReceiveHostMessage = (callback) => {
+global.setupToReceiveHostMessage = callback => {
   ipcRenderer.on('hostMessage', (event, message) => {
     callback(message);
   });