[Tools] Prepare testing plan for testing complex HTML with Handsontable

[aninde]

Description

Handsontable can be affected by changing HTML and styles. We need to test it and made some requirements.

Reference

Example https://jsfiddle.net/aninde/shu8Lg6d/ - complex HTML alter bottom overlay

https://jsfiddle.net/budnix/9paLqr43/ - without any styling

Chores

• [x] research of most popular style using with Handsontable
• [x] discussion with the team about styles
• [x] requirements preparation - can this be done without the help of UX?
• [x] preparing a plan on how to test it