Merge branch 'master' of https://github.com/lewdev/hw-gen

Improved UI experience.

Add more spacing for long multiplication equations.

Updated README

Big update

* Added Twemoji icons
* generate multiple worksheets at once and have answer key on last page.
* Subtraction & division worksheets
* single-page application
* favicons for all applications
* dedicated image

Added source code link and minor changes