Limit recipe editor width

[provokateurin]

Description
I have an ultra wide screen and the editor fills the entire width. This is not very comfortable in many places, because the input value is at the left edge and the buttons are at the right edge.

The Text app had such an adjustment recently (though in the opposite direction): nextcloud/text#6520
For this issue the same value could be chosen.

Reproduction
Steps to reproduce the behavior:

1. Have a screen with a very wide width
2. Edit a recipe

Expected behavior
There should be a limit on the width of the editor to make it more comfortable to use.

Actual behavior
The entire width is used.

Screenshots

Browser
Firefox

Versions
Nextcloud server version: 30.0.4
Cookbook version: 0.11.2
Database system: PostgreSQL