Update toolkit showcase new design

toolkit-showcase/assets/dbp-toolkit-showcase.html.ejs

toolkit-showcase/assets/favicons/android-chrome-192x192.png

toolkit-showcase/assets/favicons/android-chrome-512x512.png

toolkit-showcase/assets/favicons/apple-touch-icon.png

toolkit-showcase/assets/favicons/favicon-16x16.png

toolkit-showcase/assets/favicons/favicon-32x32.png

toolkit-showcase/assets/favicons/favicon.ico

toolkit-showcase/assets/favicons/mstile-144x144.png

toolkit-showcase/assets/favicons/mstile-150x150.png

toolkit-showcase/assets/favicons/safari-pinned-tab.svg

toolkit-showcase/package.json