Updates the angular.io landing page with new messaging
and new images. The Quick-start app has been updated
to demonstrate a minimalist Angular app and the value
proposition content has been updated.
PR Close#47047
This commit introduces a new process for generating data for the AIO
[events page](https://angular.io/events), which streamlines the process
and minimizes duplication and manual work. For more details, see
`aio/scripts/generate-events/README.md`.
PR Close#45588
Andrew Scott