bookable_resources 1.0.0-alpha3

Five commits since 1.0.0-alpha2.

Booking form
- The booking form keeps to one column on a phone. Below 40rem the room's placement in the second column opened an implicit column on a one-column grid and squeezed the whole form into a sliver beside the room's name.
- The booking rules are shown when editing a reservation too, last thing before the buttons, as they are when booking. They are a reminder of how the room is used, not a notice accepted once.
- Asking to delete a reservation: in browsers with the View Transitions API, the "Delete" link glides across the bar and becomes the red confirm button. Elsewhere, and when reduced motion is requested, the swap is instant as before.

Help
- Each help topic is written for one reader. The topics for the person who manages bookings no longer mention drush, Composer, cron, PHP or the Views UI. Installation and site set-up, and the developer topics, are listed and searched only with "Administer site configuration".
- The help search button lines up with its field.

No database updates, no configuration changes.