Add flex columns to Quill.js

This module adds a button that will allow you to add columns to the document. These columns are implement as a 1x2 table (2 columns) and as a flexbox. User should be able to e.g.
Add an image in the left column, and a text in the right. Content in the columns are 'left' and top' aligned.

- Click on the button to add columns
- The module adds two columns at the next line of the current cursor position
- The columns are visible with a light dotted border (we will override the CSS to hide them when displaying)
- The columns are stored as flexbox html with 50/50 width (please provide a seperate stylesheet for this, so we can also include that on the display page)
- When the screensize is equal or less then 640px, the columns will be shown vertically below eachother
- A user can remove columns by simply selecting the whole column and press Delete on the keyboard.

### Additional requirements:
- Should be written in Vanilla JS, no dependency on external libraries
- Well documented, compatible with all major browsers
- Written as a quill module, as explained here https://quilljs.com/guides/building-a-custom-module/

Please let me know if you have any further questions.
Buget is 100$. Please write "I can do this today" at the start of your bid.