Add option to disable spell checker

How to use GitHub

• Please use the 👍 reaction to show that you are interested into the same feature.
• Please don't comment if you have no relevant information to add. It's just extra noise for everyone subscribed to this issue.
• Subscribe to receive notifications on status change and new comments.

Is your feature request related to a problem? Please describe.
The built-in spell checker cannot be disabled. This causes unwanted visual noise (red underlines).

Describe the solution you'd like
Add a setting to disable the spell checker entirely or per input field.

Describe alternatives you've considered
Live with it. 😆 But some people don't use / don't like spell checkers. I am one of them.

Additional context
The idea was briefly mentioned here, although the issue has a different goal.