Adopt this sidewalk modal improvements

[cgansen]

Suggestions:

1. Move this legend to the column on the right. Changes:

   • Don’t use color to indicate this kind of stuff unless you test it. You’ve just ostracized 10% of your base that’s colorblind. Use patterns.
   • These are two different states, right? shoveled or not, adopted or not. So, the guide indicates the color (using high contrast colors)

2. Consistently use ‘Sign in’ and ‘Register now’ language.

3. Re-do this modal:

   1009 W. Addison St. [title]
   Nobody has adopted this sidewalk. Can you shovel this sidewalk?
   [button] Adopt this sidewalk

Hitting the button then would ask you to sign in or register to do the adoption.

(Feedback from @jdkunesh)