Adding basic paintings view (with place kittens)

- probably going to want those images to live in a model (redux)
Adding basic paintings view (with place kittens)

- main view and supporting partial
- probably going to make this a higher-level construct since multiple pages will use the approach
Updating basic paintings view to make row fluid
Fixing weird radius and shadowing
Moving _painting.html.erb to _sellable.html.erb since it will be reused elsewhere
Moving styling from index.html.erb and also using _sellable partial instead of older _painting
Minor formatting tweaks and fixing class name on index.html.erb
Updating contact information