Launched Tutorial and Use Case Templates

Given that some of the articles we launched with are tutorials (for example, Using the Remix IDE to Show Smart Contract Fees), we duplicated the template for our primer story-types, tweaked the duplicate, and saved it as our template for our tutorials. Now, we can pour our new tutorials into the correct template and our breadcrumbs (which will eventually be linkable for filtering) reflect the new story type. We also launched a new template for our forthcoming Use Case articles.