Add GUI dev environment (#114)

Setup dev tools to build GUI using ReasonML + Electron

Use react-scripts instead of custom build config

Add electron command

Rename command

gui/electron_app/index.js

@@ -0,0 +1,34 @@
+// This is the entry point of the electron app
+// It manages the overall state of the native app (menus, windows, ...)
+// TODO: launch cameradar process
+
+const { app, BrowserWindow } = require('electron');
+const path = require('path');
+const url = require('url');
+
+let mainWindow;
+
+// This method will be called when Electron has finished
+// initialization and is ready to create browser windows.
+// Some APIs can only be used after this event occurs.
+app.on('ready', () => {
+  // create the browser window.
+  mainWindow = new BrowserWindow({ width: 800, height: 600 });
+
+  // and load the index.html of the app.
+  mainWindow.loadURL(
+    url.format({
+      pathname: `${__dirname}/../build/index.html`,
+      protocol: 'file:',
+    }),
+  );
+
+  // Open the DevTools.
+  mainWindow.webContents.openDevTools({
+    mode: 'bottom',
+  });
+
+  mainWindow.on('closed', () => {
+    mainWindow = null;
+  });
+});