Add a favicon about grip HOT 4 CLOSED

Here's a few ideas to start with:

1. The GitHub icon - since that's what we'll see after pushing to GitHub, and this is meant to give you a preview of that
2. The GitHub icon modified in some way to show it's not the real thing - perhaps light grey instead of black, or with a magnifying glass to signal "preview" - though I'm not sure if GitHub allow that
3. The Markdown Mark - though that would preclude adding other formats later
4. The little book icon that GitHub are using at the top-left:
   

from grip.

I started by using GitHub's icon, but quickly realized I didn't know what was GitHub and what was Grip by glancing at the tabs. So I ended up going with the following custom icon.

Added in 1e2d1f7d1d0969445f62e6166f3d8fe7a0fa8c0d.

Thanks for the suggestion, @davejamesmiller!

from grip.

Looks good 😃

from grip.

Thanks!

from grip.