Melanie

Thanks to https://github.com/angular/material2/pull/8488 you can now use `autosize` in `mat-sidenav-container`, so you can resize the sidenav without css hacks. Here's an example adapted from the "autosize sidenav" example: https://stackblitz.com/edit/angular-b4gmby

@mackelito I think without `autosize` the main content doesn't resize properly, the sidenav overlaps it instead. But so depending on what behavior you want, I guess it can work without...