Add first version of "Workman Dead" as an alternative layout.

I've added an additional 'programmer' layout that uses 'dead' keys
for faster and easier symbol typing.
There are screenshots to explain the idea and how it works.

- Add info to README.md to explain "Workman Dead" layout and
  show how to use a 'dead' key.
- Add screenshots for different states of the "Workman Dead".
- Add an SVG file that is similar to header of workmanlayout.com
  website.