docs(bootstrap-prettify): fix $timeout issues and update related docs

End 2 end tests wait for all `$timeout`s to be run before completing the test.
This was problematic where we were using timeouts that restarted themselves because
there would never be a point when all timeouts had completed, causing the tests to hang.

To fix this $timeout had been monkey-patched but this caused other issue itself.

Now that we have $interval we don't need to use $timeout handlers that re-trigger the $timeout
so we can ditch the monkey-patch.

This commit tidies up any examples that are using this approach and changes them to use $interval
instead.

Closes #5232