Angular: Support workspace.json in nx workspace

[isaacplmann]

Issue:

What I did

Nx is a tool for managing a monorepo that can contain any kind of javascript framework. Nx has its own CLI based on the angular CLI, but we also allow the root angular.json file to be named workspace.json for non-angular devs to be more comfortable. However, the @storybook/angular package will only look for the angular.json file. This PR checks for angular.json and falls back to workspace.json. If neither file is present, the same error appears.

How to test

npx create-nx-workspace storybook-with-workspace-json --preset=empty --cli=nx
cd storybook-with-workspace-json
yarn add @nrwl/angular @nrwl/storybook
npx nx g @nrwl/angular:ng-add
npx nx g @nrwl/angular:lib ui --no-interactive
npx nx g @schematics/angular:component --name=button --project=ui --no-interactive
npx nx g @nrwl/angular:storybook-configuration --name=ui --generateStories --no-interactive
npx nx run ui:storybook

You'll see an error that angular.json was not found. After this PR, the error doesn't show up.

[ZachJW34]

Thanks @isaacplmann this will be a huge help. Hope this get reviewed soon so I can start playing around with some Angular storybook components!

[shilman]

Thanks for adding this--looks great to me. Super excited about the NX integration and would love to chat about more ways to make it better!