feat(paging): new demo for input go to usage with paging bar leveraging exposed API's

[jeremysmartt]

Description

#743

Adding a new demo to show developers how to leverage paging-bar exposed API's with a material input.

What's included?

• New demo for input usage with paging bar leveraging exposed API's
• Unit test with the input usage
• Load README.md in paging to avoid docs duplication

e.g.

<td-paging-bar #pagingBar [pageSizes]="[50,100,200,500,1000,2000]" pageLinkCount="5" [firstLast]="false" [initialPage]="1" [pageSize]="100" [total]="1345" (change)="change($event)">
  <span td-paging-bar-label hide-xs>Row per page:</span>
  {{pagingBar.range}} <span hide-xs>of {{pagingBar.total}}</span>
  <p hide-xs>Go to:</p>
  <md-input-container>
    <input #goToInput
          mdInput
          type="number"
          [min]="1"
          [max]="pagingBar.maxPage"
          [value]="pagingBar.page"
          (blur)="goToInput.value = pagingBar.page"
          (keyup.enter)="pagingBar.navigateToPage(goToInput.value); goToInput.value = pagingBar.page"/>
  </md-input-container>
</td-paging-bar>

Test Steps

• checkout branch
• ng serve
• go to http://localhost:4200/#/components/paging
• in the second demo, type in page numbers into box and see it jump to that page

General Tests for Every PR

• ng serve --aot still works.
• npm run lint passes.
• npm test passes and code coverage is not lower.
• npm run build still works.

Screenshots or link to CodePen/Plunker/JSfiddle

closes #743