Name already in use

- These templates are made following Sticker Mule's template file format.
- They include bleed, trim, and safe area lines.
- They also assume a 0.125" bleed and a 0.1" wide border in the design.

Close #15

Fixes #10. Fixes #14

This adds a link to [hexb.in](http://hexb.in/), a community curated list for hexagon logos

Adding a changelog to help members of the community understand the
differences between draft versions.

There should now be 1 sentence per line. This helps improve the
readability of intraline differences, and reduce the amount of lines
changes.

Move references to the bottom of sections, to reduce the strain required
in reading the Markdown version of the specification.

I also corrected a spelling error and linkified RFC2119.

SushiJS stickers are now Sticker Constructor Specification Draft
0 compliant!

Special thanks to Max Odgen.