Add guidelines for inputs requiring numbers 🔢

[maximedegreve]

Our form guidelines already provides a lot of good information on how to provide validation in multiple scenarios however it's missing cases where the input it limited to just numbers.

Currently there are no examples of disabled states as well as no pattern for letting the user know why an item is disabled.

Considerations

• Similar to password validation a error message should appear upon submission if it fails validations
• Similar to password validation a hint message should appear below the field explaining what's expected. In this case only numbers.
• From an accessibility point of view is it acceptable to only allow entering numbers and is there other things we should consider to ensure it is perceived correctly by screen readers.
• Do we need additional styling for the up and down arrows in number inputs
• Are there other types of inputs that might need additional documentation

Links

• Original Slack thread (internal)