Add-workforce.com

[mattkuras]

Description

This PR adds the Chicago based, Rails saas-company Workforce.com.

It includes all of the required yml keys and a logo ...

Checklist

• [x] I confirm that I've tried my best to follow the contributing instructions from the readme.
  • [ ] I needed to make an exception. I've explained it in the description above.
• [x] I've made sure that the company description is written in the third person (or left empty, since it's optional).
• [x] I've added a logo that is square, has a format of .jpeg, .png or .svg and doesn't exceed 50KB.