fix: filename references

src/index.js

@@ -2,7 +2,7 @@
 
 import ReactDOM from 'react-dom';
 import React from 'react';
-import MyApp from './MyApp.jsx';
+import MyApp from './myApp.jsx';
 // is there a better way of doing this?
 import 'ag-grid-root/dist/styles/ag-grid.css';
 import 'ag-grid-root/dist/styles/theme-fresh.css';

src/myApp.jsx

@@ -4,7 +4,7 @@ import {AgGridReact} from 'ag-grid-react';
 import RefData from './RefData';
 import RowDataFactory from './RowDataFactory';
 import ColDefFactory from './ColDefFactory.jsx';
-import './MyApp.css';
+import './myApp.css';
 
 // take this line out if you do not want to use ag-Grid-Enterprise
 import 'ag-grid-enterprise';