Typo in ad 1-on-1-voice-calling

### This issue is for a:
```
- [x] bug report -> please search issues before submitting
- [ ] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)
```

### Minimal steps to reproduce
Hi guys I have a found a typo in your webpack configuration that is blocking the app from runing:

https://github.com/Azure-Samples/communication-services-javascript-quickstarts/blob/60245b4cb793ea4cd918e633dbeb4a3c5beec340/add-1-on-1-video-calling/webpack.config.js#L19

### Any log messages given by the failure
> Webpack error when tyrint to run the app

`ERROR in unable to locate 'communication-services-javascript-quickstarts/add-1-on-1-video-calling/index.thml' glob`

### Expected/desired behavior
> Expect to run the app successfully.