Use NX for task management

[Juveniel]

closes: https://github.com/telerik/kendo-themes-private/issues/209

[tsvetomir]

You can define short package names by adding a project.json to the respective package folder, e.g.:

packages/html/package.json

{
  "name": "html",
  "$schema": "../../node_modules/nx/schemas/project-schema.json",
  "sourceRoot": "packages/html/src",
  "projectType": "library",
  "tags": []
}

[zhpenkov]

The npm run docs script fails. (env: Windows)

Edited: This was sass related issue, disregard.

[zhpenkov]

The create-screenshots script does not appear to work in this branch, and develop
(env: Windows)

[zhpenkov]

I tested the other scrips and everything looks good, the caching for compiling sass works properly.

Here are some metrics I gathered through this process (env: Windows)

Command	nx with cache	nx without cache	old
npm run sass	3s	49s	1m 15s
npm run sass:flat	2s	32s	48s
npm run sass:swatches	3s	1m	1m 50s