Provide the initial list of tools

This should be my last fairly large change to the dashboard for now. I've gone through the "Interactive Tools" list on https://calvera-test.ornl.gov/ and put each one into the dashboard and tried to categorize as best as I could. It seems like most of these applications require some level of configuration in order to run properly, which I'm considering to be a future issue for now.

Seeing this content in place made me want to tweak a few things about the UI as well, so those changes are included.

Finally, I somehow missed adding libsass to the dependency list earlier, so I've snuck that in here.

Closes #24 (closed)