Hero visual tweaks

[kpettinga]

• [x] Center position hero images
• [x] reduce height of hero spaces
• [x] move title to top of hero space
• [x] reverse scrim

[Jessdwilson]

client would like to a minimum width for hero images, perhaps 300 pixels?

[kpettinga]

@Jessdwilson this had to do with images in feature carousels, not heroes.