Add npm-run-all as a devDependency in ui.frontend.general (#1193)

[ndresgarc]

Added npm-run-all NPM package to ui.frontend.general/package.json as a devDependency entry.

Description

npm install --save-dev npm-run-all

Related Issue

Fixes #1193

Motivation and Context

I had the same problem mentioned in the issue.

How Has This Been Tested?

By running "npm run watch" and the NPM script started accorginly, opening the testing website in a new tab of the browser.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.