Use public folder rather than assets folder after the change in angular-cli's defaults for angular.json
Fixes#58981
(cherry picked from commit f2cf96b519)
To increase the ease of development we are moving @angular/docs into the adev directory within this repo. While
we are doing this to improve our development experience in the short term, efforts are also in place
to maintain a division between this @angular/docs (shared) code and adev itself, so that it can be extracted
back out in the future when components is ready to leverage it as well.
PR Close#57132