Visually document shield drawing functions

[claysmalley]

The new shield drawing functions have a lot of arguments with textual descriptions of what they do, but a documentation page with images and examples would make it significantly easier for new contributors to use them.

Planning to do this after the remaining basic shapes are converted to draw functions (triangle, pentagon, escutcheon, fishhead) and the ordering and defaulting of arguments is finalized.

[ZeLonewolf]

I might have been asleep in kindergarten, but what is this basic shape "fishhead"?

[claysmalley]

This one, used by Australia/New Zealand. Looks like it's possible to compute mathematically:

[ZeLonewolf]

Got it. Interstate shield without the frosting.