added missing webpack config file

[henrytongv]

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-essages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/NativeScript/blob/master/DevelopmentWorkflow.md#running-unit-tests.

What is the current behavior?

The example project does not work when trying to execute"ns run android". It fails with the error message "missing file webpack.config.js"

What is the new behavior?

I added the missing file. This is useful for people new to NativeScript (like me) because with this fix the project will run as-is out of the box and we can get started quickly using NativeScript

Fixes/Implements/Closes #[Issue Number].

I do not see any breaking changes

BREAKING CHANGES:

I do not see any breaking changes

Migration steps:
[Provide a migration path for existing applications.]
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By the way this link does not exist: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md

[henrytongv]

Also, the back button that appears in the detail list is missing a label. I added one.

This fix helps accessibility of the app and allows people that use a screen reader to quickly test an example app done with NativeScript

[vallemar]

@rigor789 I think this is a problem of the new version of the cli. I have had this same problem right now after updating nativescript

[rigor789]

Will look into it soon, noticed something changed but couldn't take a look before my trip.