Merge "Docs: Adds a redirect to make it easier to access Performance section on DAC." into nyc-dev

  to: /topic/libraries/support-library/index.html

- from: /billions

  to: /topic/billions/index.html

- from: /performance

  to: /topic/performance/index.html

- from: /tools/extras/support-library.html

  to: /topic/libraries/support-library/index.html

- from: /training/basics/fragments/support-lib.html