Adding Fireplace/Hearth to services list, fixing image dimensions

For images with class="thumbnail", bootstrap sets a max-width of 100% in CSS, and that overrides the width="500" that you had set in the HTML. But nothing overrides the height="500" that you had set, so instead of scaling at the appropriate aspect ratio, the image gets squished when the space is too narrow.

Also added a col-sm-6 to the two images in the services section so that they appear side-by-side on smaller screens.