Steps:

1. Add 'Products by category' block to Dashboard.
2. Configure block and enter value > 20 in 'Number of categories'.

Actual result:

The user can enter and define more than 20 categories. The chart is hardly legible at that time.

Expected result:

There should be a limit 20 and the field "Number of categories" should be validated. 

According to UX design team recommendations we should set up the limit and add helper "Min. 1, max. 20" https://www.figma.com/file/hVo2gpt7bDAPeAkhuzfVSf/Customizable-dashboard?type=design&node-id=4347%3A168163&mode=design&t=bEgEmzjLJ5a3MroK-1